domingo, dezembro 08, 2013

Astrologia e Finanças

O The Telegraph tem um longo texto sobre usar astrologia no mercado financeiro (Financial astrology: can the stars affect stocks?). É uma boa discussão que poderia servir como uma debate numa aula de administração financeira. O The Telegraph conta um pouco da história de Arch Crawford, ex-corretor que descobriu na astrologia um mecanismo de fazer projeções sobre o mercado. Hoje Crawford possui uma lista de assinantes que recebem seus conselhos por uma módica quantia.

Mas será que a astrologia tem fundamento? O jornal inglês cita a tradição de civilizações antigas e um trabalho de Nias e Eysenck para tentar descobrir a verdade e o denominado Efeito Marte: muitas pessoas famosas nasceram quando Marte esta num determinado ponto do céu e este percentual seria muito acima do acaso. Também é citado um artigo de Shawn Carlson que usou 28 astrólogos para tentar fazer projeções e o resultado foi tão bom quanto jogar uma moeda num cara ou coroa. Ou seja, astrologia é superstição.

No texto, uma frase de French, conhecido pesquisador na área de finanças:

Não é que os astrólogos vão dar -lhe algum conselho pior do que os peritos credenciados. Eles estão dando-lhe conselhos igualmente sem valor. 

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quarta-feira, outubro 19, 2011

Contador e Finanças Comportamentais



Recentemente terminei de ler o livro Pense Duas Vezes, de Michael Mauboussin (Best Business, 2011). Talvez pelo por não esperar muito da obra, foi uma surpresa agradável sua leitura. Este é um livro de finanças comportamentais e poderia ser indicado para os iniciados da área.



Veja o seguinte trecho:



Muitas decisões ruins resultam de incentivos inadequados em vez de erros. Os vieses que acompanham os incentivos, em geral, são subconscientes. Max Bazerman, professor na Harvard Business School que estuda o processo decisório, e alguns pesquisadores pediram a mais de cem contadores que revisassem cinco vinhetas contábeis ambíguas e que julgassem a contabilidade em cada uma. Metade dos contadores foi informada que tinha sido contrata pela empresa e o restante foi informado que havia sido contratados por um outra empresa. Quem desempenho o papel de auditor da empresa tinha 30% mais chances de achar que as opções estavam de acordo com os princípios contábeis, sugerindo que mesmo uma relação hipotética com a empresa afetara o julgamento. Os pesquisadores escreveram: “Talvez a característica mais notável dos processo psicológicos em ação nos casos de conflito de interesse é que eles podem ocorrer sem qualquer intenção consciente de favorecer a corrupção.” Os incentivos são um fato que contribui muito para a visão de túnel. 



Ou seja, quando um auditor comete um erro no seu parecer, talvez não seja um erro deliberado, mas uma tendência natural dos indivíduos a defenderem o ponto de vista da empresa para o qual foi contratado.


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quinta-feira, agosto 20, 2009

Honestidade

Centenas de carteiras foram deixadas nas ruas de Edinburgo, cidade da Grã-Bretanha. Destas, 240 foram devolvidas. Mas existe um aspecto interessante. Quando os pesquisadores inseriram fotografias mostrando um bebê sorrindo, um cachorrinho bonitinho, uma família feliz ou um casal de velhos o resultado mudou.
Quando a carteira tinha um bebê era mais provável receber a carteira de volta (88%). O animal de estimação, a família e o casal de velhinhos tiveram retornos de 53%, 48% e 28%, nesta ordem. Uma carteira com um cartão de uma entidade de caridade e uma carteira sem nenhum objeto diferenciado tiveram uma taxa de retorno de 20% e 15%.

Fonte: aqui

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terça-feira, junho 16, 2009

Links

segunda-feira, março 23, 2009

Racionalidade

Uma proteção contra nossos próprios impulsos irracionais
17/3/2009 - Valor Econômico

(...) A crise atual é, portando, uma grande oportunidade para que organismos de supervisão, analistas e investidores incorporem os conceitos ligados aos estudos de finanças comportamentais como complemento à Teoria Moderna de Finanças, que atualmente rege o campo das finanças. As finanças comportamentais explicam exatamente como a irracionalidade e o desconhecimento dos aspectos comportamentais podem ter fomentado a crise por meio do agravamento das perdas das carteiras.

Esses fatos, vistos inicialmente como cotidianos no ambiente de bolsa de valores, decorrem, por exemplo, da tendência dos investidores de movimentarem seus ativos na mesma direção que os demais investidores, o que produz o denominado efeito manada e a tendência à sobrerreação de quedas e subidas.

(...) Esta cegueira dos analistas é explicada na área comportamental por vários conceitos. Em um deles, o excesso de otimismo, pesquisadores comportamentais, verificaram que os analistas financeiros tendem a não acertar sobre a ocorrência de momentos de baixa dos investimentos. Além disso, verifica-se que, à medida que o mercado cai, os erros de previsão vão aumentando proporcionalmente, o que indica um viés de alta nas previsões destes profissionais.

Outro conceito é a sabedoria "ex-post", que consiste no fato de o profissional acreditar, depois de um evento já ter acontecido, que ele o previu com antecedência. A teoria comportamental mostra que quando o analista financeiro acredita que tinha previsto o resultado da crise anterior, ele pode ser levado a subestimar os demais resultados que poderiam ter ocorrido, ou seja, os cenários alternativos, o que provoca um despreparo para as situações futuras. (...)


Eduardo Camilo-da-Silva & Claudio Henrique Barbedo

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terça-feira, fevereiro 10, 2009

A Morte do Homem Racional

Um dos profetas da crise, Nouriel Roubini, que desde 2006 alertava sobre a possibilidade de um colapso no sistema financeiro, considera a relevância das finanças comportamentais na explicação dos problemas da economia mundial.

Em The Death of 'Rational Man' , David Ignatius, do The Washington Post (8/2/2009, B07) destaca o papel da leitura dos números, em especial do preço dos imóveis nos Estados Unidos, e as dicas de finanças comportamentais.

Quanto ao segundo ponto, a conclusão é simples: a teoria do homem racional não está funcionando, disse Roubini numa sessão do Fórum de Davos. E ele e outros economistas estão prestando mais atenção na questão comportamental, que inicia com as suposições sobre decisões econômicas.

Let me put in a plug here for the godfather of behavioral economics, John Maynard Keynes. His 1936 "General Theory" is often interpreted simplistically as a call for fixing recessions by boosting demand with government spending. But at a deeper level, Keynes was analyzing the role of psychological factors, such as greed and fear, in economic decisions. He understood that markets freeze when people panic and start hoarding cash. ("Extreme liquidity preference," he called it.) Conversely, economies start to roar when investors feel a surge of what Keynes called "animal spirits."

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sexta-feira, outubro 31, 2008

Finanças Comportamentais e crise

Um texto de David Brooks para o NY Times discute a crise atual sob a ótica comportamental. O texto enfatiza que a racionalidade não existiu durante a crise (como prova a reação de Greenspan, que estava chocado com o fato do mercado não ter reagido racionalmente). O texto apoia-se no último livro de Taleb (que estou tentando terminar neste momento), que usa as finanças comportamentais para enfatizar sua teoria dos cisnes negros.


OP-ED COLUMNIST
The Behavioral Revolution
By DAVID BROOKS
Roughly speaking, there are four steps to every decision. First, you perceive a situation. Then you think of possible courses of action. Then you calculate which course is in your best interest. Then you take the action.
Over the past few centuries, public policy analysts have assumed that step three is the most important. Economic models and entire social science disciplines are premised on the assumption that people are mostly engaged in rationally calculating and maximizing their self-interest.
But during this financial crisis, that way of thinking has failed spectacularly. As Alan Greenspan noted in his Congressional testimony last week, he was “shocked” that markets did not work as anticipated. “I made a mistake in presuming that the self-interests of organizations, specifically banks and others, were such as that they were best capable of protecting their own shareholders and their equity in the firms.”
So perhaps this will be the moment when we alter our view of decision-making. Perhaps this will be the moment when we shift our focus from step three, rational calculation, to step one, perception.
Perceiving a situation seems, at first glimpse, like a remarkably simple operation. You just look and see what’s around. But the operation that seems most simple is actually the most complex, it’s just that most of the action takes place below the level of awareness. Looking at and perceiving the world is an active process of meaning-making that shapes and biases the rest of the decision-making chain.
Economists and psychologists have been exploring our perceptual biases for four decades now, with the work of Amos Tversky and Daniel Kahneman, and also with work by people like Richard Thaler, Robert Shiller, John Bargh and Dan Ariely.
My sense is that this financial crisis is going to amount to a coming-out party for behavioral economists and others who are bringing sophisticated psychology to the realm of public policy. At least these folks have plausible explanations for why so many people could have been so gigantically wrong about the risks they were taking.
Nassim Nicholas Taleb has been deeply influenced by this stream of research. Taleb not only has an explanation for what’s happening, he saw it coming. His popular books “Fooled by Randomness” and “The Black Swan” were broadsides at the risk-management models used in the financial world and beyond.
In “The Black Swan,” Taleb wrote, “The government-sponsored institution Fannie Mae, when I look at its risks, seems to be sitting on a barrel of dynamite, vulnerable to the slightest hiccup.” Globalization, he noted, “creates interlocking fragility.” He warned that while the growth of giant banks gives the appearance of stability, in reality, it raises the risk of a systemic collapse — “when one fails, they all fail.”
Taleb believes that our brains evolved to suit a world much simpler than the one we now face. His writing is idiosyncratic, but he does touch on many of the perceptual biases that distort our thinking: our tendency to see data that confirm our prejudices more vividly than data that contradict them; our tendency to overvalue recent events when anticipating future possibilities; our tendency to spin concurring facts into a single causal narrative; our tendency to applaud our own supposed skill in circumstances when we’ve actually benefited from dumb luck.
And looking at the financial crisis, it is easy to see dozens of errors of perception. Traders misperceived the possibility of rare events. They got caught in social contagions and reinforced each other’s risk assessments. They failed to perceive how tightly linked global networks can transform small events into big disasters.
Taleb is characteristically vituperative about the quantitative risk models, which try to model something that defies modelization. He subscribes to what he calls the tragic vision of humankind, which “believes in the existence of inherent limitations and flaws in the way we think and act and requires an acknowledgement of this fact as a basis for any individual and collective action.” If recent events don’t underline this worldview, nothing will.
If you start thinking about our faulty perceptions, the first thing you realize is that markets are not perfectly efficient, people are not always good guardians of their own self-interest and there might be limited circumstances when government could usefully slant the decision-making architecture (see “Nudge” by Thaler and Cass Sunstein for proposals). But the second thing you realize is that government officials are probably going to be even worse perceivers of reality than private business types. Their information feedback mechanism is more limited, and, being deeply politicized, they’re even more likely to filter inconvenient facts.
This meltdown is not just a financial event, but also a cultural one. It’s a big, whopping reminder that the human mind is continually trying to perceive things that aren’t true, and not perceiving them takes enormous effort.

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quarta-feira, outubro 08, 2008

Ignóbil

A reação de Dan Ariely ao receber o prêmio Ignobil pelo trabalho em finanças comportamentais:

"I've won quite a lot of academic awards; I can't think of one that makes me happier than this one," said Dan Ariely, a Duke University economist and author of the book "Predictably Irrational: The Hidden Forces that Shape our Decisions," who said his deserving work has been passed over year after year.

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segunda-feira, abril 14, 2008

Let´s Make a Deal

Este é um problema famoso e que tem despertado interesse da pesquisa acadêmica. São três portas que você deve escolher, sendo que numa delas existe um bom prêmio (um carro, por exemplo) e em outras duas você não ganha nada. Você escolhe uma porta.

Para dar emoção ao jogo, é mostrado uma das duas portas restantes, que não tem o prêmio. Pergunta-se: você mudaria de porta?

Existem duas estratégias: permanecer com a porta ou mudar para a que restou. A lógica é mudar sempre pois a probabilidade de acerto é maior.

Aqui você pode testar isto. Clique numa das portas. Clique em Continue. Irá aparecer uma "vaca" numa outra porta. Pergunta se você quer trocar (switch) ou não (don´t switch). Clique em switch. Repita isto várias vezes e observe o placar do lado direito. O percentual de vitória será maior que 50%, como seria a intuição do jogo.

Mais, aqui.

Geralmente pensamos que devemos continuar com a escolha. Seria um caso de insistência irracional?

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segunda-feira, março 31, 2008

Finanças Comportamentais: uma visão geral


O campo de finanças comportamentais (também conhecido como Behavioral finance e behavioral economics) nasceu na década de 70 do século passado com o trabalho de Kahneman e Tversky. Antes destes dois autores, diversos pesquisadores já destacavam a importância do aspecto comportamental nas decisões financeiras/econômicas (Smith, Keynes, etc).

Em 2000 Kahneman recebeu o Nobel de Economia (Tversky já tinha falecido).

Existem diversos temas interessantes para estudar na área. Os estudos estão divididos em três grandes grupos:

a) Heurística – As pessoas tomam decisões baseadas em regras informais, que não são obtidas por análise racionais. Um exemplo simples e muito comum diz respeito uma pessoa que leu que a inflação foi de 4% ao ano e não acredita. Ela baseia sua análise nos produtos que subiram de preço, mas deixa de lado os ganhos de produtividade (computador, telefone etc) ou redução de preços de produtos lançados recentemente (TV de Plasma, por exemplo). A inflação é um cálculo muito mais complexo do que alguns poucos exemplos pessoais.

b) Framing – é a maneira como o problema é apresentado influencia a decisão. É muito comum escutar a frase que a “essência é mais importante que a forma” para indicar que os investidores têm sua atenção voltada para os fatos cruciais de uma empresa. Algumas pesquisas mostraram que em diversas situações a “forma” é importante. Uma pesquisa conduzida no final do século passado, durante a “bolha da internet”, mostrou que quando as empresas mudavam seu nome, incorporando algo que lembrava tecnologia (como o termo “com” no nome), aumentava o preço da ação da empresa. A empresa era a mesma, sem nenhuma alteração. Mas a mudança no nome (forma) tinha influencia para os investidores

c) Ineficiências do mercado – o mercado reage muito abaixo ou acima do que deveria. Uma situação já estudada corresponde ao “efeito-manada”. O nome diz muito. Quando um investidor influente resolve sair do mercado, a reação da “manada” induz o mercado a uma queda muito acima do normal.

Existem algumas situações interessantes que já foram comprovadas pelas finanças comportamentais:

=> As pessoas possuem uma grande aversão à perda. Ou seja, as pessoas não gostam de perder e esta aversão às vezes é maior do que o ganho. Um investidor que apostou no mercado acionário. O mercado caiu, mas ele insiste em manter o dinheiro até pelo menos recuperar o que aplicou (nominalmente).

=> Custo perdido. As decisões devem ser tomadas com base no futuro, sendo que aquilo que ficou para trás é um custo perdido (e não deve ser considerado na decisão). Uma pessoa comprou um apartamento e fez uma reforma. Decidindo vender o apartamento, estipula o preço com base no valor de aquisição mais o que foi gasto na reforma. O que foi gasto no passado é considerado “perdido” (ou afundado) e não deve ser considerado na decisão. O que é importante é o valor de mercado.

=> Winner´s Curse (eu gosto de chamar de Vitória de Pirro, rei grego que venceu uma batalha, mas o seu exército foi quase totalmente destruído) – Num leilão, com muitos interessados, o ganhador é um perdedor. É contraditório, mas verdadeiro. Se várias pessoas avaliam um bem leiloado em 100 reais, o ganhador provavelmente fez um lance acima deste valor.

=> Efeito propriedade – as pessoas costumam valorizar muito acima do normal os bens de sua propriedade. Uma experiência famosa deu chocolate e café para um grupo de pessoas de forma aleatória. Sabia-se, de antemão, que metade preferia café e metade chocolate. Depois de distribuído o café e o chocolate, informou-se que poderia trocar o brinde. Poucos fizeram, mostrando um apego ao bem de sua propriedade. Um dono de um carro valoriza seu bem de forma excessiva

=> Apostar em ganhadores – Você leu um anúncio que informa que um fundo de investimento apresentou o melhor rendimento do mercado. Qual a sua decisão: (a) correria para aplicar neste fundo ou (b) aplicaria no fundo que rendeu muito abaixo do mercado? A decisão correta seria a segunda. Pesquisas realizadas mostraram que os fundos perdedores possuem maiores chances de serem vencedores nos próximo período. Existem várias razões para explicar isto: (a) o fundo ganhador conseguiu este feito graças ao acaso; (b) o mercado poderá observar com mais atenção o fundo ganhador e tentar antecipar sua decisão; (c) a atração de novos investidores torna difícil o fundo ganhador ter flexibilidade suficiente para ajustar ao mercado. Ou seja, a bola de cristal não funciona todo dia. Este efeito é conhecido como reversão à média.

Bibliografia sobre o assunto em língua portuguesa:

O livro “Proteja seu dinheiro de você mesmo”, da Editora Futura, de autoria de Belsky e Gilovich tenta aplicar Finanças comportamentais a situações diárias de investimento.

“Investimento sob Medida”, IBEP, é de Achiles Mosca, que escreve alguns artigos sobre o tema.

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terça-feira, março 25, 2008

Finanças Comportamentais segundo Greenspan


Segundo Zubin Jelveh este texto é o triunfo da behavioral economics. Greenspan reconhece os problemas da irracionalidade do mercado. Grifo meu.

We will never have a perfect model of risk
By Alan Greenspan
Published: March 16 2008, Financial Times

The current financial crisis in the US is likely to be judged in retrospect as the most wrenching since the end of the second world war. It will end eventually when home prices stabilise and with them the value of equity in homes supporting troubled mortgage securities.

Home price stabilisation will restore much-needed clarity to the marketplace because losses will be realised rather than prospective. The major source of contagion will be removed. Financial institutions will then recapitalise or go out of business. Trust in the solvency of remaining counterparties will be gradually restored and issuance of loans and securities will slowly return to normal. Although inventories of vacant single-family homes – those belonging to builders and investors – have recently peaked, until liquidation of these inventories proceeds in earnest, the level at which home prices will stabilise remains problematic.

The American housing bubble peaked in early 2006, followed by an abrupt and rapid retreat over the past two years. Since summer 2006, hundreds of thousands of homeowners, many forced by foreclosure, have moved out of single-family homes into rental housing, creating an excess of approximately 600,000 vacant, largely investor-owned single-family units for sale. Homebuilders caught by the market’s rapid contraction have involuntarily added an additional 200,000 newly built homes to the “empty-house-for-sale” market.

Home prices have been receding rapidly under the weight of this inventory overhang. Single-family housing starts have declined by 60 per cent since early 2006, but have only recently fallen below single-family home demand. Indeed, this sharply lower level of pending housing additions, together with the expected 1m increase in the number of US households this year as well as underlying demand for second homes and replacement homes, together imply a decline in the stock of vacant single-family homes for sale of approximately 400,000 over the course of 2008.

The pace of liquidation is likely to pick up even more as new-home construction falls further. The level of home prices will probably stabilise as soon as the rate of inventory liquidation reaches its maximum, well before the ultimate elimination of inventory excess. That point, however, is still an indeterminate number of months in the future.

The crisis will leave many casualties. Particularly hard hit will be much of today’s financial risk-valuation system, significant parts of which failed under stress. Those of us who look to the self-interest of lending institutions to protect shareholder equity have to be in a state of shocked disbelief. But I hope that one of the casualties will not be reliance on counterparty surveillance, and more generally financial self-regulation, as the fundamental balance mechanism for global finance.

The problems, at least in the early stages of this crisis, were most pronounced among banks whose regulatory oversight has been elaborate for years. To be sure, the systems of setting bank capital requirements, both economic and regulatory, which have developed over the past two decades will be overhauled substantially in light of recent experience. Indeed, private investors are already demanding larger capital buffers and collateral, and the mavens convened under the auspices of the Bank for International Settlements will surely amend the newly minted Basel II international regulatory accord. Also being questioned, tangentially, are the mathematically elegant economic forecasting models that once again have been unable to anticipate a financial crisis or the onset of recession.

Credit market systems and their degree of leverage and liquidity are rooted in trust in the solvency of counterparties. That trust was badly shaken on August 9 2007 when BNP Paribas revealed large unanticipated losses on US subprime securities. Risk management systems – and the models at their core – were supposed to guard against outsized losses. How did we go so wrong?

The essential problem is that our models – both risk models and econometric models – as complex as they have become, are still too simple to capture the full array of governing variables that drive global economic reality. A model, of necessity, is an abstraction from the full detail of the real world. In line with the time-honoured observation that diversification lowers risk, computers crunched reams of historical data in quest of negative correlations between prices of tradeable assets; correlations that could help insulate investment portfolios from the broad swings in an economy. When such asset prices, rather than offsetting each other’s movements, fell in unison on and following August 9 last year, huge losses across virtually all risk-asset classes ensued.

The most credible explanation of why risk management based on state-of-the-art statistical models can perform so poorly is that the underlying data used to estimate a model’s structure are drawn generally from both periods of euphoria and periods of fear, that is, from regimes with importantly different dynamics.

The contraction phase of credit and business cycles, driven by fear, have historically been far shorter and far more abrupt than the expansion phase, which is driven by a slow but cumulative build-up of euphoria. Over the past half-century, the American economy was in contraction only one-seventh of the time. But it is the onset of that one-seventh for which risk management must be most prepared. Negative correlations among asset classes, so evident during an expansion, can collapse as all asset prices fall together, undermining the strategy of improving risk/reward trade-offs through diversification.

If we could adequately model each phase of the cycle separately and divine the signals that tell us when the shift in regimes is about to occur, risk management systems would be improved significantly. One difficult problem is that much of the dubious financial-market behaviour that chronically emerges during the expansion phase is the result not of ignorance of badly underpriced risk, but of the concern that unless firms participate in a current euphoria, they will irretrievably lose market share.

Risk management seeks to maximise risk-adjusted rates of return on equity; often, in the process, underused capital is considered “waste”. Gone are the days when banks prided themselves on triple-A ratings and sometimes hinted at hidden balance-sheet reserves (often true) that conveyed an aura of invulnerability. Today, or at least prior to August 9 2007, the assets and capital that define triple-A status, or seemed to, entailed too high a competitive cost.

I do not say that the current systems of risk management or econometric forecasting are not in large measure soundly rooted in the real world. The exploration of the benefits of diversification in risk-management models is unquestionably sound and the use of an elaborate macroeconometric model does enforce forecasting discipline. It requires, for example, that saving equal investment, that the marginal propensity to consume be positive, and that inventories be non-negative. These restraints, among others, eliminated most of the distressing inconsistencies of the unsophisticated forecasting world of a half century ago.

But these models do not fully capture what I believe has been, to date, only a peripheral addendum to business-cycle and financial modelling – the innate human responses that result in swings between euphoria and fear that repeat themselves generation after generation with little evidence of a learning curve. Asset-price bubbles build and burst today as they have since the early 18th century, when modern competitive markets evolved. To be sure, we tend to label such behavioural responses as non-rational. But forecasters’ concerns should be not whether human response is rational or irrational, only that it is observable and systematic.

This, to me, is the large missing “explanatory variable” in both risk-management and macroeconometric models. Current practice is to introduce notions of “animal spirits”, as John Maynard Keynes put it, through “add factors”. That is, we arbitrarily change the outcome of our model’s equations. Add-factoring, however, is an implicit recognition that models, as we currently employ them, are structurally deficient; it does not sufficiently address the problem of the missing variable.

We will never be able to anticipate all discontinuities in financial markets. Discontinuities are, of necessity, a surprise. Anticipated events are arbitraged away. But if, as I strongly suspect, periods of euphoria are very difficult to suppress as they build, they will not collapse until the speculative fever breaks on its own. Paradoxically, to the extent risk management succeeds in identifying such episodes, it can prolong and enlarge the period of euphoria. But risk management can never reach perfection. It will eventually fail and a disturbing reality will be laid bare, prompting an unexpected and sharp discontinuous response.

In the current crisis, as in past crises, we can learn much, and policy in the future will be informed by these lessons. But we cannot hope to anticipate the specifics of future crises with any degree of confidence. Thus it is important, indeed crucial, that any reforms in, and adjustments to, the structure of markets and regulation not inhibit our most reliable and effective safeguards against cumulative economic failure: market flexibility and open competition.

The writer is former chairman of the US Federal Reserve and author of ‘The Age of Turbulence: Adventures in a New World’


Já segundo Levitt e List

Perhaps the greatest challenge facing behavioral economics is demonstrating its applicability in the real world. In nearly every instance, the strongest empirical evidence in favor of behavioral anomalies emerges from the lab. Yet, there are many reasons to suspect that these laboratory findings might fail to generalize to real markets.

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terça-feira, dezembro 04, 2007

Estratégia de Marketing e FC

Numa compra existiam as seguintes opções:
Lento = US$14 (entrega em 15 de dezembro)
Rápido = US$18 (entrega em 10 de dezembro)
Expresso = US$18 (entrega em 5 de dezembro)

Parece interessante pagar os mesmos 18 dólares e receber 5 dias antes. Mas a opção colocada é para que o cliente pague o Expresso. Isto funciona? Aparentemente sim.

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sábado, novembro 10, 2007

Como se divide as pesquisas em Finanças Comportamentais

O número de pesquisas possíveis em Finanças Comportamentais é bastante significativo. Em especial quando levamos em consideração a possibilidade de fazermos adapatções as pesquisas realizadas lá fora.

Mas a tentativa de classificação destas pesquisas pode ser interessante e ajudar ao futuro pesquisador (e também ao leitor).

Apresento aqui duas classificações possíveis: pelo "método" e pelo tema.

Pelo tema da pesquisa, Hersh Shefrin, em Beyond Greed and Fear, Oxford University Press, Oxford, 2007, apresenta os três temas da área, que apresento, adaptado, abaixo:

1. Os investidores cometem erros em razão do uso de macetes? Finanças comportamentais acredita que sim, muito embora isto não seja considerado pelas Finanças Tradicionais. Estes "macetes" são denominados de regras heurísticas para o processamento das informações.

2. Pode a forma influenciar os investidores? Este é um problema de estudo de frame. Finanças comportamentais acredita que sim, mas para as finanças tradicionais o que importa é a essência.

3. Os erros e os problemas de frames influenciam o mercado? Para finanças comportamentais sim; já as finanças tradicionais considera que o mercado como um todo é racional, ou melhor, eficiente.

Uma outra forma de entender os estudos de finanças comportamentais é quando ao "método". Esta é uma classificação do autor deste blog e pretende mostrar como são realizadas as pesquisas na área. Existem duas formas básicas:

a) Através de questionários, como foi o caso dos trabalhos clássicos iniciais. Neste caso são construídas situações que tentam reproduzir certo tipo de problema para verificar as questões listadas anteriormente. Neste caso, submete-se os questionários para pessoas responderem, sem a preocupação de fazer um vínculo direto com o mercado. A grande vantagem desta alternativa é a facilidade de execução da pesquisa. Entretanto, o problema é a possibilidade de distanciar da realidade dos problemas financeiros.

b) Usando dados do mercado para obter situações onde as finanças tradicionais podem falhar. Diversos estudos foram realizados nesta situação, inclusive o estudo clássico de De Bondt e Thaler de 1985.

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quinta-feira, maio 31, 2007

Discussão Thaler e Rizzo sobre Comportamento Humano

O Wall Street Journal promoveu uma discussão entre Thaler e Rizzo sobre o comportamento humano. A seguir a reprodução da discussão:

Should Policies Nudge People
To Make Certain Choices?

Driven by research in behavioral economics that suggests people don't always act in their own best interests, some economists are arguing for new policies that would challenge traditional "hard" tools for changing behavior, such as sin taxes and outright bans.

Such policies would often rely on default options that nudge, steer and coax -- but don't force -- individuals to make certain choices. Is this sensible governance? The Online Journal asked Mario Rizzo, a professor of economics at New York University and director of NYU's Program on the Foundations of the Market Economy, and Richard Thaler, professor of economics and behavioral science at the University of Chicago's Graduate School of Business, to hash it out.

What do you think? Share your comments on our discussion board.

* * *


Richard Thaler writes: Behavioral economics is founded on the unremarkable observation that human beings are imperfect decision makers. They have limited information-processing abilities, willpower, memory and attention. As a result, they make predictable errors by their own lights. Many Americans think of themselves as overweight; most 401(k) participants think they are saving too little; and nearly everyone thinks of himself as forgetful.

In light of human limitations, Cass Sunstein and I argue for policies that we call libertarian paternalism. Although the phrase sounds like an oxymoron, we contend that it is often possible to design policies, in both the public and private sector, that make people better off -- as judged by themselves -- without coercion. We oppose bans; instead, we favor nudges.

Consider two examples, both designed to increase savings. The first is to enroll people, automatically, into savings plans -- while allowing them to opt out. The second is the Save More Tomorrow plan, which allows employees to commit themselves now to increasing their savings rates later, when they get raises. Both approaches have been remarkably successful.

Well-chosen default rules are examples of helpful "choice architecture." Since it is often impossible for private and public institutions to avoid picking some option as the default, why not pick one that is helpful?

* * *


Mario Rizzo writes: The decisions of individuals may be imperfect but can the legal paternalist successfully steer them toward better decisions?

I say legal paternalist because Cass Sunstein and Richard Thaler clearly do not object to using coercion at the level of framing decisions. For example, they seem to approve of employers' being legally required to provide automatic 401(k) enrollment unless the employee opts out. But they also approve of mandatory cooling-off periods for consumer purchases; these cooling-off periods absolutely prevent individuals from concluding immediate exchanges even at lower prices.

It is a good thing to help people make better decisions. But law requires us to go beyond intention. What is the appropriate standard for better decisions? Thaler and Sunstein say it's what people would do if they had "complete information, unlimited cognitive abilities, and no lack of willpower." This is a very ambitious standard that could tax the abilities of even well-meaning policymakers.

Can we discover "true" preferences through individuals' statements that they are too fat and save too little? Talk is cheap. These could be expressions of mere desire, not a real willingness to make trade-offs between values. We all want to have more savings and more consumption, too.

Moreover, the public sector is not governed by science or even by behavioral economists, but by ambitious people with limited cognitive abilities, lack of willpower, and faulty memories, not to mention expanding waistlines. Whom should we trust more: individuals who face the costs and benefits of their own choices, or politicians and bureaucrats who do not?

Richard Thaler writes: It is both wrong and misleading to characterize libertarian paternalism as primarily an activity of governments. Automatic enrollment and Save More Tomorrow have been adopted in thousands of companies with no governmental involvement. When the government does get involved, we prefer nudges to requirements. A good example is the 2006 Pension Protection Act. Under that law, firms that offer to at least partially match their employees' contributions, enroll their employees automatically, and automatically escalate their contribution rates are given a waiver from some burdensome paperwork. No coercion is involved.

We agree that it can be difficult to determine people's true preferences. And it is an axiom of behavioral economics that intentions do not always -- or even usually -- lead to action. But statements of good intention can signal a desire for help in following through. Many employees have voluntarily signed up for the Save More Tomorrow program, and very few subsequently quit. We do not think that many people would sign up for "Smoke More Tomorrow," or "Eat More French Fries Tomorrow."

We agree that government workers are human. We are also happy to go on the record stipulating that politicians are boundedly rational. Some are also dishonest. Some are even fat. However, what are the implications of these obvious facts? Do we want to charge our political leaders with the task of making people worse off?

Often nudges are inevitable. Where they aren't, we agree that unless there is a good showing of need, government might do best to stand aside.

* * *


Mario Rizzo writes: Is New Paternalism primarily about advising private individuals and firms? If so, why use a political term -- libertarian -- to identify it?

It's true, some firms have adopted automatic 401(k) enrollment policies -- while fewer have adopted the Save More Tomorrow program. The market allows for this diversity while eliminating ineffective or inappropriate plans. No libertarian I know of has ever opposed privately adopted options. If this is all Thaler is saying, what's new?

But Thaler and Sunstein do go beyond this. Elsewhere, they've argued for costly contractual provisions like vacation time, allowing only termination for cause, non-waivable cooling-off periods, maximum 40-hour work weeks, and -- presumably -- the legal requirement of automatic savings plan enrollment, if not enough firms voluntarily adopt it. All this is said to be consistent with "libertarian paternalism."

Thaler says that those automatically enrolled in 401(k)s haven't quit, so they must be benefiting. This is an odd claim for a behavioral economist. Why would failure to change indicate a benefit? When the default is non-enrollment, Thaler says that individuals tend to stay in it because they're irrationally biased toward keeping the status quo.

The mistakes of bureaucrats, politicians and voters aren't as likely to be corrected by individual or social processes as errors made in the private sphere. Why? Because bureaucrats and politicians don't care about private welfare as much as individuals do and voters don't have much incentive to become informed. So people -- who make imperfect decisions -- tend to do less harm if they "nudge" only themselves and not others through policy choices.

* * *


Richard Thaler writes: I am glad Mario agrees with our private initiatives on retirement savings in which firms have nudged rather than required employees to take certain beneficial actions. Surveys of employers suggest that a majority will be offering automatic features by next year, a big step forward. Of course, the fact that few employees opt out is partly due to inertia, but most employees do get around to joining the plan under opt in, so the main gain from automatic enrollment is to get people to join sooner, something they appreciate.

Mario's major complaints are with positions that we do not advocate, namely what he calls the "legal imposition of costly contractual presumptions." We have never suggested that any particular contractual form be imposed, including automatic enrollment. See my previous post. Instead we stress that when governments do write laws, especially those mandating -- rather than nudging -- some action, they should do so with an eye toward making people better off. We do admit to liking some mandated -- and thus non-libertarian -- cooling-off periods under certain circumstances, as when buyers are especially likely to have made decisions under undue selling pressure. Who amongst us has not bought something under pressure that he would like to undo the next morning?

Mario's main misconception is that government can avoid nudging. It can't. The rules of the common law are legal rules that governments write. Whether governments are more or less corrupt than the private sector is an empirical question, and there are surely many examples of dumb or unethical behavior in both sectors. But this is beside the point. We favor better government, not more government. We urge both sectors to adopt libertarian paternalistic policies.

* * *


Mario Rizzo writes: I repeat: "Is New Paternalism primarily about advising private individuals and firms? If so, why use a political term -- libertarian -- to identify it?" It is simply a management-consulting philosophy.

If a firm chooses a default option, it is by no means inevitable that it must choose on the basis of paternalistic criteria. Under purely voluntary conditions, it will choose so as to enhance the attractiveness of its compensation package, that is, according to the actual preferences of its employees. Its goal is to maximize profits. To anticipate what employees or consumers want is the market principle, not paternalism. I repeat: "If this is all Thaler is saying, what's new?"

If automatic enrollment proves popular in the long run, then, at least most people must be aware of their procrastination bias -- assuming it exists -- and want to overcome it. The previously hostile legal environment had prevented employers from responding to this de-biasing preference.

As to the more intrusive examples of paternalism mentioned in my previous post, Richard and Cass Sunstein have indeed argued that they are consistent with libertarian paternalism. Let the reader decide.

The standard Richard advances that "when governments do write laws, especially those mandating -- rather than nudging -- some action, they should do so with an eye toward making people better off" may seem innocuous, but it is actually dangerous. This is because just about anything can slip by. (Satisfaction of informed preferences is an obscure criterion of "better off.") Such a standard could set in motion a slippery slope to much more intrusive interventions, especially in a world of boundedly rational individuals who tend to view the world in a narrow frame. It does not take corrupt public officials to go down this road. Self-interest and bounded rationality are quite enough.

* * *


Richard Thaler writes: Let's recapitulate. People make mistakes, so sometimes they can be helped. It is possible to help without coercion. That is libertarian paternalism. The concept can be and is used in both the public and private sectors. For example, in London, pedestrians from abroad are reminded by signs on the pavement to "look right" because their instincts from back home are to expect traffic to approach from the left. No one is forced to look right, but fewer pedestrians are hit by trucks.

Another example comes from Sweden, which launched a partial privatization of their social security system in 2000. The plan was open to any fund, which meant that participants faced 456 options. There was also a very well-designed default fund -- using private managers selected by the government -- that offered global diversification at very low fees (16 basis points). By any standard, both ex ante and ex post, the participants who selected their own portfolio of funds did worse than those who took the default plan. The main mistake the government made in designing this plan was to discourage participants from choosing the default fund, perhaps thinking, as Mario does, that choosing for oneself is always the best approach.

Mario thinks we are naïve about government. We think he is naïve about firms. Does he think that the companies that offered stock options to student loan officers to induce them to feature their loans had the "actual preferences" of the students at heart? Maximizing profits does not always mean maximizing the welfare of the customers.

Finally Mario seems to have a phobia about slippery slopes. I guess he thinks that if governments start with signs that say "look right," the next thing you know we will have Prohibition coming back. By the same logic, we should worry that if libertarians succeed in eliminating rent control that we will be soon down the slippery slope toward anarchy. Slippery slope arguments should be avoided unless there is proof that the slope is greased. In our case, by insisting, as we do, on only libertarian paternalism, the slope runs into a brick wall before it even gets started. And besides, what is the alternative? Inept neglect?

* * *


Mario Rizzo writes: Libertarianism is a political philosophy that seeks to reduce the activities of the state to a very low level. It is very much about less government. Paternalism is a political or moral philosophy that seeks to override the actual or operative preferences of individuals for their own benefit, however defined, according to Donald VanDeVeer's 1986 book on the subject. When applied to the actions of government, paternalism cannot be libertarian. It can only be more or less intrusive.

Does Richard wish to reduce his "libertarian paternalism" to the appropriate management of government-owned streets or other enterprises? In the London case, what people want is obvious: They don't want to get hit by cars. London is doing what entrepreneurs generally do: satisfying actual preferences. London is mimicking the market.

In Sweden, the government actively discouraged people from relying on the default investment option. People probably interpreted this as meaning the default option was not very good. They succumbed to this unfortunate inference because they viewed the government as an authoritative investment adviser. Government provision of investment advice is not consistent with libertarianism. But if it does provide advice, is it paternalistic to provide it in such a way that people make reasonable inferences? If Vanguard provides good advice, is that paternalism? In each case, this is just satisfying actual preferences for advice. (Note that none of this requires reference to the idea of "true" or "informed" preferences about which so big a deal was made.)

Richard wants to use the word "libertarian" to differentiate his paternalism from the traditional variants. Yet he uses the word in a fuzzy way. He wants to define libertarian along a continuous variable -- the cost of exercising the exit option. However, libertarianism, as every libertarian understands it, uses a bright-line test -- who imposes the cost? The authors of the concept of "libertarian paternalism" have said that clearly intrusive/coercive interventions are consistent with it. See my previous post. And they have also said, explicitly, that there is no sharp line between libertarian and non-libertarian paternalism. Thus, Richard cannot claim that his standard creates a bright-line rule that would help us resist the slippery slope.

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Emoções e decisões morais

Um artigo de Fernando Reinach, que escreve semanalmente no Estadão, sobre finanças comportamentais.

Emoções e decisões morais Artigo
O Estado de São Paulo, p.a21

Fernando Reinach

A relação entre a moral e as emoções é parte subjacente da trama de grande parte dos romances, filmes e novelas.

Nossas decisões morais são influenciadas por nossas emoções ou seriam as emoções efeitos de nossos conflitos morais? Até recentemente esse tipo de problema pertencia ao campo da filosofia e da psicologia, mas agora neurocientistas estão abordando essas questões experimentalmente.

Imagine que você se defronte com o seguinte problema: um pequeno vagão vem descendo sem controle por um trilho que desemboca em uma bifurcação. Cabe a você operar um comando que determina se o vagão vai para a direita ou para a esquerda. Se você desviá-lo para a esquerda ele vai atropelar e matar cinco pessoas. Se você desviá-lo para a direita ele vai matar uma única pessoa.

Diante desse dilema moral, a grande maioria das pessoas escolhe a solução do mal menor: desvia o vagão para a direita sacrificando um para salvar cinco. Imagine agora que o vagão vem descendo a ladeira em direção às cinco pessoas, mas, antes, vai passar por baixo de uma ponte. Você está em cima da ponte e tem de tomar uma decisão. Ou não faz nada e deixa as cinco pessoas morrerem ou agarra uma pessoa que está em cima da ponte e a lança sobre os trilhos para parar o vagão.

Apesar de o número de pessoas mortas ser idêntico em cada opção (cinco mortes ao invés de uma), a grande maioria das pessoas prefere deixar as cinco pessoas morrerem a tomar a atitude de fisicamente jogar uma pessoa inocente nos trilhos e causar sua morte.

Recentemente, esse e outros experimentos do mesmo tipo foram repetidos com pacientes com uma lesão no córtex pré-frontal. Seis pacientes foram escolhidos pelo fato de terem lesões causadas por tumores ou por derrames em uma região específica do cérebro que, se destruída, reduz a capacidade da pessoa de sentir emoções como empatia, culpa ou vergonha.

Apesar de não sentirem essas emoções, os pacientes tinham capacidade de raciocínio e inteligência normais. O que foi observado é que os pacientes com a lesão tomavam as mesmas decisões que as pessoas normais quando as escolhas morais não envolviam aspectos sentimentais muito próximos ao indivíduo. Assim, nos exemplos acima, esses pacientes reagiram da mesma maneira que pessoas normais no caso do desvio do vagão.

Ao contrário das pessoas normais, mesmo quando a decisão envolvia pessoas próximas, os pacientes com a lesão tendiam a escolher a opção lógica. No exemplo da ponte, não hesitavam em atirar uma pessoa da ponte para salvar outras cinco. A conclusão desse estudo é que nossas decisões morais são intrinsecamente dependentes de fatores emocionais, mas que essa influencia só altera o julgamento quando a decisão moral envolve pessoas ou situações muito próximas ao sujeito.

Esse resultado não é inesperado, afinal a própria Justiça reconhece que o julgamento moral das pessoas pode ser bloqueado quando a decisão envolve pessoas ou situações muito próximas a cada um de nós. O interessante é que, pela primeira vez, se obtém comprovação experimental para essa observação, inclusive com o mapeamento das regiões do cérebro envolvidas nos fenômenos. Aos poucos a biologia vai explicando fenômenos mentais que antes pareciam exclusividade da filosofia.

Mais informações em Damages to the prefrontal córtex increases utilitarian moral judgements, na Nature, volume 446, página 908, 2007.

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Sorte no mercado chinês

Uma reportagem do Wall Street Journal, 28/05/2007, mostra como a questão da superstição afeta o investimento no mercado acionário chinês:

Nas bolsas chinesas, a chave está no '8'
James T. Areddy, The Wall Street Journal
The Wall Street Journal Americas

XANGAI — Quando um amigo lhe deu várias dicas de investimentos acionários no ano passado, Yan Caigen comprou 30.000 ações de uma delas, uma fabricante de cimento. O motivo: o código da empresa, 600881, continha dois auspiciosos oitos.

"Eu acredito que bons códigos dão boa sorte", diz Yan, que passa quase todos os seus dias diante do monitor na corretora Shenyin & Wanguo Securities Co., de Xangai. De fato, a ação da Jilin Yatai Group Co., a fabricante de cimento em que ele apostou, rapidamente triplicou, gerando um lucro de US$ 50.000. Yan atribui o desempenho aos dois "8" no código numérico da ação, que ele considera uma combinação que dá sorte.

Parte superstição, parte profecia auto-realizável, a numerologia é uma estratégia básica da negociação de ações na China. Ela mostra como é amplamente disseminada na sociedade chinesa a crença de que os números contêm pistas para a boa sorte.

É uma crença pouco notada e que vem alimentando a alta das bolsas da quarta maior economia do mundo, cuja influência sobre outros mercados acionários tem crescido, como ficou evidente em fevereiro, quando uma forte queda em Xangai derrubou bolsas ao redor do planeta, de Frankfurt a São Paulo. O Índice Composto de Xangai subiu mais de 56% neste ano e já quadruplicou seu nível de meados de 2005, uma alta que vem gerando temores de uma bolha no mercado.

O fervor dos investidores com a numerologia também ajuda a explicar por que o governo chinês não tem conseguido esfriar o entusiasmo nas bolsas através de medidas convencionais, como a restrição ao crédito na semana passada.

Para observadores do mercado, a confiança dos investidores chineses no poder profético dos números — em vez de fundamentos econômicos, como perspectivas de negócios ou lucro — é um dos muito sinais de que o investimento nas bolsas de Xangai ou de Shenzhen parece uma jogatina.

As corretoras são organizadas como se fossem cassinos. Os investidores tomam chá, fumam e conversam enquanto negociam em máquinas parecidas com caça-níqueis. Em vez de colocar moedas, eles passam o cartão para pagar pelas ações.

"Somos investidores individuais. Geralmente escolhemos às cegas qual ação vamos comprar", diz Chen Guoan, investidor de Xangai. Alguns distribuem cigarros para congratular os amigos quando a ação sobe.

Pessoas comuns, que geralmente entendem pouco ou nada de finanças, representam de 60% a 80% dos investidores na China. Nos Estados Unidos, por exemplo, o mercado é dominado por gigantes financeiros como Goldman Sachs Group Inc., Merrill Lynch & Co. e Fidelity Investments Inc. "Vêem-se coisas estranhas com as ações, com números e códigos da sorte", diz Jing Ulrich, presidente de investimentos na China do J.P. Morgan Chase & Co. "Isso reflete um mercado muito imaturo."

A maioria da classe média urbana da China não tem dinheiro nos quase 100 milhões de contas de corretagem do país. Novos investidores em número recorde, geralmente com pouco conhecimento sobre a mecânica do mercado, também estão entrando de cabeça nas bolsas, abrindo em média mais de 100.000 novas contas por dia neste ano. O governo já alertou para o perigoso nível de especulação, já que os investidores estão financiando suas compras de ações com empréstimos ou cartões de crédito. Nas últimas semanas, o valor diário do volume de transações chegou a quase US$ 50 bilhões.

A falta de uma imprensa livre na China e as restrições que as autoridades impõem ao que os analistas podem dizer publicamente deixam os investidores vulneráveis a teorias de negociação inusitadas. Eles em geral se valem de conselhos como o de usar roupas vermelhas, que representam um mercado "aquecido", e a evitar referências ao "pai", já que a palavra em chinês é homônima para "queda".

— Tang Hanting e Ellen Zhu colaboraram neste artigo.

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quarta-feira, maio 23, 2007

Regras e Comportamento

As pessoas reagem as regras. Esta é uma verdade que tem sido comprovada diariamente. Um estudo interessante mostra uma aplicação disto nas corridas da Nascar. Este tipo de corrida inspirou a Stock Cars brasileira.

Desde 2003 a Nascar criou duas etapas. Numa primeira etapa, os corredores da Nascar tentam classificar para a etapa final, onde somente os dez primeiros colocados participam. A etapa final possui dez corridas. Isto mudou os incentivos dos corredores.

Se um corredor está fora dos dez primeiros, ele irá arriscar mais sua corrida para tentar obter uma boa classificação. Isto, naturalmente, pode resultar em acidentes ou em carros que não terminam a corrida.

O estudo citado acima mostra que a probabilidade de um acidente aumentou com a mudança de regras. Usando uma regressão linear, com variável binária (ou dummy), o autor do blog encontrou resultados expressivos.

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domingo, maio 20, 2007

Linha do tempo em Finanças Comportamentais

A linha do tempo de Finanças Comportamentais, usando o Google Timeline, é interessante. O ápice ocorre no final da década de 1990 (1999). Será que o interesse em Finanças Comportamentais diminuiu?

Clique aqui e veja

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segunda-feira, março 26, 2007

Entrevista com Thaler

Uma interessante entrevista com Richard Thaler, para o New Yorke Times Magazine (11/02/2001) (via Game Theory Readings) realizada por Roger Lowenstein. Lowenstein escreve livros de finanças (um deles sobre Buffett). Destaquei, no texto abaixo, os trechos que achei interessante (em negrito) como o desprezo dos economistas clássicos e o estudo da garrafa de vinho.

Exuberance Is Rational
New York Times Magazine
11 February 2001
New York Times Magazine


Or at least human. Richard Thaler has led a revolution in the study of economics by understanding the strange ways people behave with their money.
by Roger Lowenstein



It is possible that Richard Thaler changed his mind about economic theory and went on to challenge what had become a hopelessly dry and out-of-touch discipline because, one day, when a few of his supposedly rational colleagues were over at his house, he noticed that they were unable to stop themselves from gorging on some cashew nuts he'd put out. Then again, it could have been because a friend admitted to Thaler that, although he mowed his own lawn to save $10, he would never agree to cut the lawn next door in return for the same $10 or even more. But the moment that sticks in Thaler's mind occurred back in the 1970's, when he and another friend, a computer maven named Jeff Lasky, decided to skip a basketball game in Rochester because of a swirling snowstorm.

"But if we had bought the tickets already, we'd go," Lasky noted.

"True -- and interesting," Thaler replied.

Thaler began to make note of these episodes -- anomalies, he called them -- and to chalk them up on his blackboard at the University of Rochester, where he was a young, unheralded and untenured assistant professor. Each of these stories was at odds with neoclassical economics as it was taught in graduate schools; indeed, each was a tiny subversion of the prevailing orthodoxy. According to accepted economic theory, for instance, a person is always better off with more rather than fewer choices. So why had Thaler's colleagues roundly thanked him for removing the tempting cashews from his living room? The lawn example was even more troubling. Perhaps you dimly remember from Economics 101 that unlovely term, "opportunity cost." The idea, as your pointy-headed prof vainly tried to persuade you, is that forgoing a gain of $10 to mow a neighbor's lawn "costs" just as much as paying somebody else to mow your own. According to theory, you either prefer the extra time or the extra money -- it can't be both. And the basketball tickets refer to "sunk costs." No sense going to the health club just because we have paid our dues, right? After all, the money is already paid -- sunk. And yet, Thaler observed, we do. People, in short, do not behave like the pointy heads say they should.

In the ordered world of economics, this rated as a heresy on the scale of Galileo. According to the standard or neoclassical school (essentially a 20th-century updating of Adam Smith), people, in their economic lives, are everywhere and always rational decision makers; those who aren't either learn quickly or are punished by markets and go broke. Among the implications of this view are that market prices are always right and that people choose the right stocks, the right career, the right level of savings -- indeed, that they coolly adjust their rates of spending with each fluctuation in their portfolios, as though every consumer were a mathematician, too. Since the 1970's, this orthodoxy has totally dominated the top universities, not to mention the Nobel Prize committee.

Thaler spearheaded a simple but devastating dissent. Rejecting the narrow, mechanical homo economicus that serves as a basis for neoclassical theory, Thaler proposed that most people actually behave like . . . people! They are prone to error, irrationality and emotion, and they act in ways not always consistent with maximizing their own financial well being. So serious was Thaler's challenge that Merton Miller, the late Nobelist and neoclassical deity, refused to talk to him; Thaler's own thesis adviser lamented that he had wasted a promising career on trivialities like cashews. Most economists simply ignored him.

But the anomalous behaviors documented by Thaler and a band of fellow dissenters, including Yale's Robert Shiller and Harvard's Lawrence Summers, Clinton's last treasury secretary, have grown too numerous to ignore. And the renegades, though still a minority, have embarked on a second stage: an attempt to show that anomalies fall into recognizable and predictable patterns. The hope is that by illuminating these patterns, behavioral economics, as it has come to be called, will yield a new understanding of the economy and markets. Behaviorism, says Daniel McFadden, the recent Nobel laureate, "is a fundamental re-examination of the field. It's where gravity is pulling economic science."

Thaler, after years of being shunned, is now a popular, highly paid professor at the University of Chicago Graduate School of Business, the traditional nerve center of neoclassicism. His increasing following is owed in no small part to the fact that behaviorism, unlike so much of economics, is fun. Although prewar economists like John Maynard Keynes were literary artists, most writing in the field since the 70's has been obtuse and highly mathematical, all but inaccessible to the lay person. By contrast, Thaler's papers are rich with intuitive gems drawn from sports, business and everyday life. In one paper, he pointed out that people go across town to save $10 on a clock radio but not to save $10 on a large-screen TV. It's a seemingly obvious point -- and also a direct contradiction of rationalist theory.

Thaler loves pointing out that not even economics professors are as rational as the guys in their models. For instance, a bottle of wine that sells for $50 might seem far too expensive to buy for a casual dinner at home. But if you already owned that bottle of wine, having purchased it earlier for far less, you'd be more likely to uncork it for the same meal. To an economist (a sober one, anyway) this makes no sense. But Thaler culled the anecdote from Richard Rosett, a prominent neoclassicist.

A thickset man of 55, Thaler has a sharp wit and a voluble ego. Many assume that his years in the academic wilderness have made him defensive; Thaler denies it. "The last thing I want to do is to sound embittered about having to struggle," he told me, easing his Audi around Lake Michigan toward the Gothic stone campus. But Thaler doesn't so much debate opponents; he skewers them. The British economist Ken Binmore once proclaimed at a seminar that people evolve toward rationality by learning from mistakes. Thaler retorted that people may learn how to shop for groceries sensibly because they do it every week, but the big decisions -- marriage, career, retirement -- don't come up that often. So Binmore's highbrow theories, he concluded, were good for "buying milk."

I met Thaler two days after the election, and he was already predicting that the country would be willing to accept Bush as the winner, because "people have a bias toward the status quo." I asked how "status-quo bias" affects economics, and Thaler observed that workers save more when they are automatically enrolled in savings programs than when they have to choose to participate by, say, returning a form. Standard theory holds that workers would make the most rational decision regardless.

Savings is an area where Thaler thinks he can have a big impact. Along with Shlomo Benartzi, a collaborator at U.C.L.A., Thaler cooked up a plan called Save More Tomorrow. The idea is to persuade employees to commit a big share of future salary increases to their retirement accounts. People find it less painful to make future concessions because pain deferred is, to an extent, pain denied. Therein lies the logic for New Year's resolutions. Save More Tomorrow was tried with a Chicago company, and workers tripled their savings within a year and a half -- an astounding result. "This is big stuff," Thaler says. He is shopping the plan around to other employers and predicts that eventually it could help raise the country's low savings rate.

Though Thaler, who comes across as a middling, Robert Rubin-style Democrat, plays down the connection, such results could provide ammunition to liberals who think government bashing has gone too far. Since the Reagan era, a mantra for office seekers is that people know what is best for themselves. Generally, yes; but what if not always, and what if they err in predictable ways? For instance, Thaler has found that the number of options on a 401(k) menu can affect the employees' selections. Those with a choice of a stock fund and bond fund tend to invest half in each. Those with a choice of three stock funds and one bond fund are likely to sprinkle an equal amount of their savings in each, and thus put 75 percent of the total in stocks. Such behavior illustrates "framing" -- decisions being affected by how choices are positioned. Political pollsters and advertisers have known this for years, though economists are just coming around.

Framing has big implications for the debate on privatizing Social Security. Neoclassicists say that people should manage their own retirement accounts, and that the more choices they have the better. Thalerites are not so sure. "If Thaler is right, it makes the current dogmatic antipaternalism really doubtful," says Cass Sunstein, a prominent legal scholar at the University of Chicago.

Thaler, who grew up in Chatham, N.J., the son of an actuary, wrote his doctoral thesis at the University of Rochester on the economic "worth" of a human life (public planners tackle this morbid theme frequently, for instance, in determining speed limits). Thaler conceived a clever method of calculation: measuring the difference in pay between life-threatening jobs like logging and safer lines of work. He came up with a figure of $200 a year (in 1967 dollars) for each 1-in-1,000 chance of dying.

Sherwin Rosen, his thesis adviser, loved it. Thaler did not. He had been asking friends about it, and most insisted that they would not accept a 1-in-1,000 mortality risk for anything less than a million dollars. Paradoxically, the same friends said they would not be willing to forgo any income to eliminate the risks that their jobs already entailed. Thaler decided that rather than rationally pricing mortality, people had a cognitive disconnect; they put a premium on new risks and casually discounted familiar ones.

For a while, Thaler regarded such anomalies as mere cocktail-party fodder. But in 1976 he happened upon the work of two psychologists, Daniel Kahneman and the now-deceased Amos Tversky, who had been studying many of the same behaviors as Thaler. The two had noticed a key pattern: people are more concerned with changes in wealth than with their absolute level -- a violation of standard theory that explained many of Thaler's anomalies. Moreover, most people are "loss averse," meaning they experience more pain from losses than pleasure from gains. This explains why investors hate to sell losers. For Thaler, their work was an epiphany. He wrote to Tversky, who plainly encouraged him. "He took me seriously," Thaler recalled, "and because of that, I started taking it seriously."

Thaler began designing experiments to test his ideas. In one, Thaler told lab subjects to imagine they are stranded on a beach on a sweltering day and that someone offers to go for their favorite brand of beer. How much would they be willing to pay? Invariably, Thaler found, subjects agree to pay more if they are told that the beer is being purchased from an exclusive hotel rather than from a rundown grocery. It strikes them as unfair to pay the same. This violates the bedrock principle that one Budweiser is worth the same as another, and it suggests that people care as much about being treated fairly as they do about the actual value of what they're paying for. Although "fairness" is generally ignored by neoclassicists, it's probably a reason why companies do not lower salaries when they encounter tough times -- perversely, laying off workers is considered more fair.

Thaler's first paper on anomalies was rejected by the leading economic journals. But in 1980, a new publication, The Journal of Economic Behavior and Organization, was desperate for copy, and Thaler's "Toward a Positive Theory of Consumer Choice" saw the light of day. "I didn't have any data," he admits. "It was stuff that was just true."

The response from fellow economists was zero. But the article eventually caught the eye of Eric Wanner, a psychologist at the Alfred P. Sloan Foundation in New York. Wanner was itching to get economists and psychologists talking to one another, and Thaler took the bait. "He was the first economist who thought hard about the implications for economics," Wanner says. "The reaction of mainstream economists was defensive and hostile. They considered it an attack -- an apostasy." Wanner, who became president of the Russell Sage Foundation, started financing behavioral economics, and Thaler became the informal leader, organizing seminars and summer workshops. In effect, he turned an idea into a movement.

"Dick was like a taxonomist who goes out and collects embarrassing specimens," Wanner says. "He learned that to get anyone to pay attention to him he had to develop a portfolio of facts that he could be entertaining about and that economists couldn't sweep under the rug."

Thaler's most original contribution was "mental accounting" -- an extension of Kahneman and Tversky's "framing" principle. "Framing" says the positioning of choices prejudices the outcome. "Mental accounting" says people draw their own frames, and that where they place the boundaries subtly affects their decisions. For instance, a poker player who accounts for each day separately may become bolder at the end of a winning night because he feels he is playing with "house money." If he accounted for each hand separately, he would play the first and last hands the same.

Most people sort their money into accounts like "current income" and "savings" and justify different expenditures from each. They'll gladly blow their winnings from the office football pool, a "frivolous" account, even while scrupulously salting away every penny of their salaries.

Thaler and a trio of colleagues went on to document that cabdrivers stop working for the day when they reach a target level of income. (Each day's "account" is separate.) This means that -- quite nonsensically -- they work shorter hours on more lucrative days, like when it's raining, and longer hours on days when fares are scarce! In a sense, investors who pay attention to short-term fluctuations are like those cabbies; if they toted up their stocks less frequently, they would be better investors. Thaler went so far as to suggest to an audience at Stanford that investors should be barred from seeing their portfolios more than once every five years.

Such irreverence reinforced the view among economists that Thaler could be safely ignored. His anecdotes were fuzzy science, they said, and examples like the cabbies were easy pickings. Since there is no way for a third party to profit from a cabbie's mistake, it's not surprising that he would make one. Thaler knew the criticism had merit, and that to be taken seriously, he had to demonstrate irrationalities in financial markets, which are the purest embodiment of neoclassicism. In the markets, one person's bad decision can be offset by someone else's smart one. Across the markets, rationality should reign.

Thaler set out to prove that it did not. His first effort, a 1985 paper with Werner De Bondt, his doctoral student, showed that stocks tend to revert to the mean -- that is, stocks that have outperformed for a sustained period are likely to lag in the future and vice versa. This was a finding that Chicago School types couldn't ignore -- according to their theory, no pattern can be sustained, since if it did, canny traders would try to profit from it, correcting prices until the pattern disappeared.

Then, in 1987, Thaler was hired to write a regular Anomalies column for a new economics journal, giving him a widespread audience among his peers. That same year, the stock market crashed 23 percent on a single day. Thaler could hardly have imagined better proof that the market was not, well, perfectly rational. More economists began to mine the data, and by the 90's there was a rich literature of market anomalies, documenting, for example, that people can consistently make money on stocks that trade at low multiples of earnings, or on companies that signal changes by doing things like hiking dividends. Documenting anomalies became a popular pastime from Berkeley to Harvard.

Thaler still has plenty of critics. The harshest one is right upstairs from his office at Chicago, the curmudgeonly Eugene Fama, a longtime advocate of the efficient-market school. "What Thaler does is basically a curiosity item," Fama snipes. "Would you be surprised that every shopper doesn't shop at the lowest prices? Not really. Does that mean that prices aren't competitive?"

Thaler periodically invites Fama in to his class to present the other side, but Fama has not returned the gesture and, indeed, sounds bitter that behavioral finance is getting so much attention. "One question that occurs to me," Fama says, "is, 'How did some of this stuff ever get published?"' The objection raised most often, from Fama and others, is that if Thaler is right and the market is so screwy, why wouldn't more fund managers be able to beat it? A variation of this theme is that if behavioral economics, for all its intuitive appeal, can't help people make money, what good is it?

Thaler, actually, is a director in a California money management firm, Fuller & Thaler Asset Management, which, according to figures it provided, has been beating the market handily since 1992. The firm tries to exploit various behavioral patterns, like "categorization": when Lucent Technologies was riding high, people categorized it as a "good stock" and mentally coded news about it in a favorable way. Lately, Lucent has become a "bad stock." But Thaler, who does not get involved in picking stocks, stops short of suggesting that investors versed in his research can beat the market. Mispricings that spring from anomalies are hard to spot, he says, particularly when the people looking for them are prone to their own behavioral quirks.

If this sounds muted, it may be because Thaler is ready to declare victory and join the establishment. The neoclassical model, he admits, is a fine starting point; it's misleading only when regarded as a perfect or all-encompassing description. People aren't crazy, he adds, but their rationality is "bounded" by the tendencies that Kahneman, Tversky, himself and others have studied. What he hopes is that a future generation will resolve the schism by building behavioral tendencies into a new, more flexible model.

For now, Thaler is still looking for new miniature applications wherever he can find them, like on the basketball court recently. Thaler studied games in which a team trails by 2 points, with time left for just one shot. What to go for, 2 points or 3? A 2-point shot succeeds about half the time, a 3-pointer about 33 percent of the time. But since a 2-point basket would only tie the game (and force an overtime, in which the team has a 50-50 chance of winning), going for a 3-pointer is a superior strategy. Still, most coaches go for 2. Why? Because it lowers the risk of sudden loss. Coaches, like the rest of us, do more to avoid losing than they do to win. You won't find an explanation for that in the mechanical homo economicus of theory. But it has everything to do with folks Thaler thinks are much more relevant to the economy -- Homo sapiens.

Copyright 2001 The New York Times Company

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sábado, março 03, 2007

Os melhores são os piores

A revista Fortune tem realizado uma pesquisa sobre a reputação das empresas norte-americanas (America's Most Admired Companies). Apesar de não ser um levantamento sobre investimento, pesquisas acadêmicas têm analisado o desempenho das ações das empresas escolhidas na lista das mais admiradas (e também das menos admiradas). O resultado não é conclusivo, mas alguns estudos mostram que existe uma relação inversa entre admiração e desempenho da empresa como investimento.

Um exemplo é um estudo, citado pela própria revista Fortune (5/3/2007, vol. 155, n. 4, Sometimes the Worst are First), que analisa o desempenho de 1983 a 2006, período do prêmio da revista.

As empresas menos admiradas tiveram um retorno de 17,8%; as mais admiradas, 15,4%. No período, a SP500 teve um retorno de 11,2%. Como isso é possível?

Um dos autores do estudo, Meir Statman, diz que uma possível explicação está nas finanças comportamentais. Para Statman, os investidores tem sentimentos positivos sobre o sucesso de empresas como GE e P&G que pagam um preço mais elevado para ter suas ações. Ou seja, as empresas mais admiradas possuem um P/L maior (média de 2,07 versus 1,27 das menos admiradas). Além disso, as mais admiradas tendem a possuir maior capitalização no mercado.

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