Inflação atinge os 6%

Calma, não é essa inflação. A inflação medida pelo Eurostat está mesmo abaixo da meta, a rondar 0s 0,5%. E com tendência para descer – pelo menos se olharmos para onde devemos olhar, que é para a core inflation.

Mas se perguntarem a um europeu qual é a sua percepção, então 6% é provavelmente a resposta que vão obter. A Comissão Europeia fez um estudo acerca de percepções e realidade, e concluiu que, apesar de não passaram completamente ao lado dos preços que pagam nas lojas, os europeus avaliam a inflação em níveis sistematicamente acima dos valores registados nos dados oficiais.


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Investimento Público: uma comparação alternativa

Um dos exemplos mais engraçados da relevância da Economia Comportamental (sigam o link se não conhecem, e depois vão a correr ler isto) é o regime de subscrições da Economist.

Economist tem – ou tinha, há uns anos – três opções de assinatura: a) assinatura on-line por 59$; b) assinatura da versão impressa por 125$; e c) assinatura de ambas as versões por 125$. O que parece estranho, porque ninguém no seu perfeito juízo preferiria pagar 125$ para ter a versão impressa quando pode ter o pacote completo pelo mesmo montante. O que é a opção b) está ali a fazer? Será a Economist assim tão cega que não perceba que ninguém vai escolher esta opção?

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Ciência comportamental e políticas públicas

Uma mind note para quem tem curiosidade sobre o assunto: no The Irish Economy, Liam Delaney publicou uma óptima compilação de estudos, papers e livros acerca do novo e vibrante campo das ciências comportamentais. O ‘chapéu’ abarca temas tão diversos como as finanças comportamentais, a ‘economia da felicidade’, neuroeconomia, psicologia e muitos outros ramos que têm em comum o estudo dos processos de escolha do ser humano através de métodos empíricos (por oposição às teorias da preferência revelada). A maioria das ligações não se limita a expor investigação, explorando também as suas implicações para várias políticas públicas.

Curvas de indiferença comportamentais

A economia comportamental já aí anda há uns anos, mas até agora tem sido encarado mais como uma compilação dispersa de descobertas interessantes do que propriamente como uma parte integrante da teoria económica mainstream. Mas isso está a mudar e pode ler-se, no Vox, uma proposta para começar a incorporá-la na microeconomia: Sticky prices and beahavioural indifference curves.

According to conventional indifference curve diagrams, when deciding between two goods – say, food and clothing – it is as though we’ve never consumed them before. Thus, we are assumed to come to the problem in a pristine state, without indicating the amount of the goods in question we consumed in the prior period or are adapted to. However, this is contradictory, because if we have not consumed these items before, how are we supposed to know how much utility we should expect from them?

Hence, the customary indifference curve depends on the implicit assumption that choices along indifference curves are reversible. That is, if an individual owns x and is indifferent between keeping it and trading it for y, then when owning y the individual should be indifferent about trading it for x. If loss aversion is present, however, this reversibility will no longer hold (Knetsch 1989, Kahneman et al. 1991). Knetsch and Sinden (1984) were the first to point out that the standard assumption pertaining to the equivalence of losses and gains is contradicted by the experimental evidence.


In sum, behavioural indifference curves are relative to a reference point. The endowment effect implies that people are willing to give up an object only at a higher price than the price at which they are willing to buy it, i.e. it is psychologically more difficult to give up an object than to acquire it. This changes the shape and properties of the indifference map, which has far-reaching implications not only in classrooms, but also in applied areas such as the evaluation of welfare states and the stickiness of economic variables such as wages, prices, and interest rates (Knetsch et al. 2012). This salient issue ought no longer to be ignored, and needs a much wider research agenda than hitherto allotted to it at the margins of the discipline.

Even at this stage it is important to incorporate behavioural indifference curves into the curriculum and stop teaching outdated concepts. If you think that behavioural indifference curves would be too complicated for beginners then I would urge you not to teach the conventional ones until the students are ready for the current version, because one should not mislead students by teaching inappropriate concepts. If the straight-talking Nobel-prize-winning physicist Richard Feynman (1918–1988) were still with us, he would concur with this view. In his famous 1974 commencement address at the California Institute of Technology, he beseeched the graduating class to practice scientific integrity, utter honesty, and to lean over backwards so as not to fool themselves (and of course others) (Feynman 1985). I believe that the same is true for us – teachers of economics, it is time to start leaning over backwards and to stop teaching the standard indifference curves.


A economia do futebol

Cognitive biases in football punditry, por Chris Dillow. Este é daqueles textos que nos obriga a pensar. Por um lado, é óbvio que o comentário futebolístico é animado pelos enviesamentos cognitivos mais gritantes. Por outro lado, é difícil imaginar como seria possível comentar um jogo de forma minimamente razoável. «A equipa foi goleada, mas é estatisticamente inevitável que resultados destes aconteçam de vez em quando, pelo que é prematuro fazer uma avaliação da qualidade intrínseca do plantel» é tudo o que um adepto não quer ouvir. Para serem minimamente razoáveis, os comentários teriam de ser absolutamente inodoros. Talvez uma boa dose de irracionalidade seja o preço a pagar para podermos gozar o jogo.

Football might be the world’s most popular sport, but moaning about co-commentators runs it a close second: so far, Clarke Carlisle, Andy Townsend and Phil Neville have all trended on Twitter and not in a good way.

One reason – or at least justification – for this contumely is that their judgments are often clouded by numerous cognitive biases; I’ve long suspected that Daniel Kahneman could have re-written Thinking Fast and Slow by taking examples solely from football punditry.

Here is an (incomplete) inventory of these biases:

1. Hindsight bias. How often after a player shoots wide, does Andy Townsend say he could have passed instead? It’s easy to know the right thing to do when you’ve seen what went wrong. This is especially true when discussing defences. Pointing out that the defensive shape was wrong after it conceded a goal is not good enough; the question is: did that same shape prevent many other goals? Americans call this Monday morning quarterbacking: it’s a shame there’s no English equivalent.

2. Outcome bias. Results shape our perceptions of performance. For example the Netherlands’ 5-1 defeat of Spain looks like a tonking. But their third goal might have been disallowed; their fourth was due to an unusually bad goalkeeping error and their fifth caught a demoralized side on the break. It’s a cliche – because it’s true – that football is a game of small margins, but if those margins all drop in your favour you can achieve a great result without a proportionately superior performance.

3. Misperceiving randomness. There’s always one team at a World Cup that does surprisingly well. This, though, is only to be expected. A lot of teams have a small but reasonable chance of getting to, say, the quarter-final. Across 32 teams, one of those chances is likely to turn up – just as we are likely to win a prize if we buy enough lottery tickets.

4. The hot-hand fallacy. This is a tendency to see “form” where none really exists but merely a run of luck. Take, for example, a player who scores a goal every other game – roughly Suarez’s and van Persie’s record but less that Dzeko’s. Over a 50-game career, such a player has a 50-50 chance of scoring six goals in six games. Such a run could well be enough to win him a golden boot and legendary status. A variation of this fallacy is the “commentator’s curse” – when a commentator praises a player only to see him shank a pass horribly. What happens in such cases is that an in-game run of luck suddenly stops.

5. Bayesian conservatism. Once we’ve got an idea that a team or player is rubbish, we interpret evidence to back up this idea; this is seen in co-commentators repeating themselves. My prior is that Diego Costa is a nasty cheating traitor who will therefore fit in well at Chelsea; I doubt this will change.

6. Selective perception. This is closely related to conservatism. It’s our tendency to notice evidence that supports our priors more than evidence that contradicts it. So if we have an idea that someone is a good player, we’ll spot his good points more than his bad; this is especially likely because so much of what players do (or don’t do) happens when they don’t have the ball; do they make good runs, or track back well?

7. Over-reaction. For example, Uruguay looked poor last night. Is this because they are a genuinely mediocre side (as their qualifying recordsuggests) or is it because they had an off-day? We can’t tell for sure on the basis of 90 minutes. If we do so, we might well be over-reacting.

8. Overconfidence. Everyone thinks their opinions on football are the correct ones, in part because we underweight our vulnerablity to all of the above; this is the Dunning-Kruger effect. One example of this is that many of us are backing Brazil to win the cup. But in fact, although they are favourites the smart money thinks there’s a 75% chance they won’t win.

Of course, cognitive biases aren’t necessarily wrong; indeed, they persist precisely because they sometimes (often) lead us to the right conclusion. And sometimes, they can cancel out; for example, Bayesian conservatism offsets over-reaction. My point is merely that one reason why pundits so often annoy us is that they are prone to such biases – and, of course, we are morely likely to see such biases in others than in ourselves.


Dinheiro e sentido de voto

Mais um artigo interessante no Vox. Os autores fazem um estudo inédito em que seguem as preferências políticas de vários eleitores, alguns dos quais ganharam a lotaria. Aparentemente, quanto maiores forem os valores ganhos, maior a tendência para a preferência política se enviesar progressivamente para a direita. Money makes people right-wing and inegalitarian, por Andrew Oswald e Nattavudh Powdthavee.

We are able to observe people before and after a win. Access to longitudinal information gives us advantages denied to most previous researchers on this topic. One reason this is important is because it seems plausible that personality might determine both the number of lottery tickets bought and the political attitudes of the person, and this might thereby lead to a possible spurious association between winning and right-leaning views. We provide, among other kinds of evidence, a simple graphical demonstration that winners disproportionately lean to the right having previously not been right-wing supporters.


The consequences of winning even a modest sum of money are fairly large – certainly a number of percentage points extra on your chances of favouring a Mrs Thatcher or a Ronald Regan. Thus money makes people right-wing and inegalitarian. Perhaps even you.

Paradoxo de Easterlin revisitado

Uma curiosa reavaliação do Paradoxo de Easterlin, segundo o qual a riqueza não traz felicidade (embora ajude). GDP and life satisfaction: new evidence, no Vox.

Our econometric analysis implies that long-term GDP growth is certainly desirable among poorer countries, but is it a desirable feature among developed countries as well? Recent evidence shows the negative effect of high aspiration can also be rationally predicted by individuals who, nevertheless, may still choose options that may not seem to maximise happiness, but which are compatible with high-income aspirations.

This implies that individuals may still prefer to live in richer countries, even if this would result in a decreased level of life satisfaction. In other words, the fact that individuals aspire to a higher income may not be considered – from an individual perspective – a negative feature of an economy even if this might result in a lower level of reported life satisfaction among the richest countries.

Sexo (e economia)

Mais de dois séculos depois da fundação da economia como disciplina autónoma, a pergunta original que levou Adam Smith a escrever The Wealth of Nations continua por responder: o que é que causa o crescimento económico de longo prazo? O campo é fértil em conjecturas – liberdade económica (Smith), hábitos (Landes), estabilidade macroeconómica (FMI), factores geográficos (Diamond), os genes (Clark) – mas os consensos são poucos.

Em Sexual selection, conspicuous consumption and economic growth, três investigadores da Universidade de Austrália concluem que os homens já sabiam. É tudo uma questão de sexo.

O paper é puramente teórico, na linha de alguns modelos da biologia evolutiva. Os autores partem da observação de Robert Trivers de que machos e fêmeas têm estratégias reprodutivas diferenciadas, de maneira a maximizar o sucesso reprodutivo. Os homens, para quem os filhos são um investimento barato (apenas o tempo de copular), procuram sexo indiscriminado; as mulheres, para quem os filhos consomem recursos (nove meses de gestação no mínimo), perdem tempo a garantir a escolha de um parceiro que garanta apoio na criação da criança (fidelidade) e capacidade para o fazer adequadamente (poder económico).

Nos modelos habituais da biologia evolutiva, os machos reagem a esta selectividade através da sinalização destes traços: oferecem presentes (muito comum em alguns insectos – e em determinados primatas superiores…), fazem demonstrações de força (combates), etc. Na economia, como na biologia, a sinalização só funciona se o sinal tiver custos associados, de maneira a que nem todos os possam emitir.

O paper mostra como o consumo conspícuo (consumo ‘de luxo’, para ostentar poder e riqueza) pode funcionar como um destes sinais, incentivando so homens a consumirem sempre mais e a incorrerem nos comportamentos necessários à manutenção deste consumo – muitas horas trabalhadas, inovação, produtividade, etc. Este estudo é congruente, aliás, com investigação recente que dá conta de que o aumento da desigualdade leva a um aumento na concessão de crédito junto das faixas sociais mais baixas.

Cito, em baixo, um trecho retirado do excelente Stumbling and Mubling, acerca do mesmo estudo:

Perhaps, therefore, men work longer than necessary in part simply because they want to shag around.

This suggests that economic growth will be n-shaped with respect to sex. Where there are strong taboos against non-marital sex, the motive for conspicuous consumption will be weak – because it’ll not get you sex anyway – and so labour supply and innovation and growth will be weak. But where women give it up for anyone, there’ll be no need for men to spend to impress, so growth will also be weak. It’s middling degrees of sexual promiscuity that are best for growth.

History is consistent with this. Max Weber relates how, in traditionalist societies, it was very hard to get men to work more than the bare minimum – though he had very different ideas as to how this habit was overcome! And economic growth in such societies tends to be negligible.

By contrast, growth in the west was fastest in the 1950s and 60s when traditional sexual morality weakened, and  – as Mad Men shows us – economically successful men could shag around.