Homo infidelis : preferências, assimetria de informação e signaling

No presente trabalho analisamos a eficácia de estratégias de signaling no contexto do relacionamento extra-diádico. Adicionalmente, mensuramos tanto as preferências declaradas quanto as reveladas pelos indivíduos em suas interações no ambiente virtual, comparando gêneros e países. Pesquisas anteriores sobre a temática extra-diádica apoiaram-se excessivamente sobre metodologias com substanciais lacunas: baixo número de observações, universo amostral restrito a estudantes universitários, viéis auto-declaratório comprometendo a correta interpretação da realidade dos fatos, e ausência de comparativos internacionais. Todas essas ponderações foram superadas no presente estudo, no qual analisamos 100 mil indivíduos, sendo 6 mil homens e 4 mil mulheres para cada um dos 10 países da amostra: Argentina, Austrália, Brasil, Canadá, Chile, Itália, México, Espanha, Reino Unido e Estados Unidos. Assim, temos um universo amostral plúrimo em termos de nacionalidade e número de observações. As evidências empíricas aqui reveladas mostraram que indivíduos do sexo masculino são mais ativos na conquista extra-conjugal, refutando a sugestão de uma convergência comportamental. Homens contactaram em média per capita 30 mulheres diferentes no horizonte temporal de 3 meses, contra 13 na direção oposta. Em termos de preferências físicas, constatamos que indivíduos de âmbos os gêneros procuram consumar a relação com uma contraparte idealizada. Mulheres mostram interesse por homens altos e experientes. Os homens querem mulheres mais novas e em forma. Homens baixos ou novos, e mulheres altas ou velhas, foram os mais rechaçados da amostra. Com relação às preferências declaradas e reveladas sobre o tipo de encontro extra-diádico almejado, tanto homens quanto mulheres mostraram maior interesse por um “caso rápido”, indicando o intuito de estabelecer um contato pouco aprofundado, casual, de cunho físico-sexual e com baixa vinculação afetiva. A opção menos escolhida foi “um caso virtual”, sugerindo a efetiva intenção de concretizar a infidelidade, e não mantê-la restrita ao ambiente virtual. Por fim, verificamos que as estratégias de signaling analisadas (por meio de foto, feedback e presente virtual) foram fortemente eficazes. Em todos os casos indivíduos que adotaram tais sinalizações obtiveram substancial vantagem competitiva em relação aos demais e passaram a exercer maior atratividade, recebendo elevada parcela de mensagens e contatos.

Education, preferences for leisure, and the optimal income tax schedule

Recent advances in dynamic Mirrlees economies have incorporated the treatment of human capital investments as an important dimension of government policy. This paper adds to this literature by considering a two period economy where agents are di erentiated by their preferences for leisure and their productivity, both private information. The fact that productivity is only learnt later in an agent's life introduces uncertainty to agent's savings and human capital choices and makes optimal the use of multi-period tie-ins in the mechanism that characterizes the government policy. We show that optimal policies are often interim ine cient and that the introduction of these ine ciencies may take the form of marginal tax rates on labor income of varying sign and educational policies that include the discouragement of human capital acquisition. With regards to implementation, state-dependent linear taxes implement optimal savings, while human capital policies may require labor income taxes that depend directly on agents' schooling.

Income inequality in a job-search model with heterogeneous time preferences

This paper explores the use of an intertemporal job-search model in the investigation of within-cohort and between-cohort income inequality, the latter being generated by the heterogeneity of time preferences among cohorts of homogenous workers and the former by the cross-sectional turnover in the job market. It also offers an alternative explanation for the empirically-documented negative correlation between time preference and labor income. Under some speciÖc distributions regarding wage offers and time preferences, we show how the within-cohort and between-cohort Gini coe¢ cients of income distribution can be calculated, and how they vary as a function of the parameters of the model.

Local concavifiability of preferences and determinacy of equilibrium

In this paper we consider strictly convex monotone continuous complete preorderings on R+n that are locally representable by a concave utility function. By Alexandroff 's (1939) theorem, this function is twice dífferentiable almost everywhere. We show that if the bordered hessian determinant of a concave utility representation vanishes on a null set. Then demand is countably rectifiable, that is, except for a null set of bundles, it is a countable union of c1 manifolds. This property of consumer demand is enough to guarantee that the equilibrium prices of apure exchange economy will be locally unique, for almost every endowment. We give an example of an economy satisfying these conditions but not the Katzner (1968) - Debreu (1970, 1972) smoothness conditions.

Preferences, common knowledge and speculative trade

We study the proposition that if it is common knowledge that en allocation of assets is ex-ante pareto efficient, there is no further trade generated by new information. The key to this result is that the information partitions and other characteristics of the agents must be common knowledge and that contracts, or asset markets, must be complete. It does not depend on learning, on 'lemons' problems, nor on agreement regarding beliefs and the interpretation of information. The only requirement on preferences is state-additivity; in particular, traders need not be risk-averse. We also prove the converse result that "no-trade results" imply that traders' preferences can be represented by state-additive utility functions. We analyze why examples of other widely studied preferences (e.g., Schmeidler (1989)) allow "speculative" trade.

Beyond indifferent players: on the existence of prisoners dilemmas in games with amicable and adversarial preferences

Why don’t agents cooperate when they both stand to gain? This question ranks among the most fundamental in the social sciences. Explanations abound. Among the most compelling are various configurations of the prisoner’s dilemma (PD), or public goods problem. Payoffs in PD’s are specified in one of two ways: as primitive cardinal payoffs or as ordinal final utility. However, as final utility is objectively unobservable, only the primitive payoff games are ever observed. This paper explores mappings from primitive payoff to utility payoff games and demonstrates that though an observable game is a PD there are broad classes of utility functions for which there exists no associated utility PD. In particular we show that even small amounts of either altruism or enmity may disrupt the mapping from primitive payoff to utility PD. We then examine some implications of these results.

Homothetic preferences

This paper describes properties of upper semi-continuous homothetic preferences. First we give conditions for the existence of an upper semi-continuous representation which is homogeneous of degree one. Then we show that with the additional assumptions of monotonicity or strict convexity, the preference is continuous. Several counterexamples illustrate the tightness of the results.

Interim efficiency with MEU-preferences

Recently Kajii and (2008) proposed to characterize interim efficient allocations in an exchange economy under asymmetric information when uncertainty is represented by multiple posteriors. When agents have Bewley's incomplete preferences, Kajii and Ui (2008) proposed a necessary and sufficient condition on the set of posteriors. However, when agents have Gilboa--Schmeidler's MaxMin expected utility preferences, they only propose a sufficient condition. The objective of this paper is to complete Kajii and Ui's work by proposing a necessary and sufficient condition for interim efficiency for various models of ambiguity aversion and in particular MaxMin expected utility. Our proof is based on a direct application of some results proposed by Rigotti, Shannon and Stralecki (2008).

Uma análise empírica sobre as preferências do consumidor brasileiro de cervejas artesanais

Um dos produtos mais consumidos do mundo vem passando por grandes transformações, e a cerveja que conhecemos como tipo Pilsen (Light Lager) deixou de ser opção única nas prateleiras. Dado o potencial de crescimento do setor no Brasil, o objetivo deste trabalho é mapear as preferências do consumidor de cerveja artesanal, usando técnicas de preferência declarada, a partir da aplicação de questionários que convidam o entrevistado a elencar suas preferências diante das combinações dos atributos Cor, Paladar, Aroma e Álcool. A partir da estratificação da amostra em Idade e Experiência, os resultados indicam que Paladar, seguido da Cor e, por último, o Aroma são os atributos mais relevantes para o entrevistado Experiente, enquanto o Não Experiente atribui maior peso à Cor, seguida do Paladar, sendo o Aroma um atributo irrelevante em suas escolhas. O atributo Álcool revelou-se insignificante em todas as estratificações realizadas.

Phase transition of demand explained by the heterogeneity of consumers' intrinsic preferences

In 1991 Gary S. Becker presented A Note on Restaurant Pricing and Other Examples of Social In uences on Price explaining why many successful restaurants, plays, sporting events, and other activities do not raise their prices even with persistent excess demand. The main reason for this is due to the discontinuity of stable demands, which is explained in Becker's (1991) analysis. In the present paper we construct a discrete time stochastic model of socially interacting consumers deciding for one of two establishments. With this model we show that the discontinuity of stable demands, proposed by Gary S. Becker, depends crucially on an additional factor: the dispersion of the consumers' intrinsic preferences for the establishments.

Asymmetric preferences in investment decisions in the Brazilian financial market

The main objective of this article is to test the hypothesis that utility preferences that incorporate asymmetric reactions between gains and losses generate better results than the classic Von Neumann-Morgenstern utility functions in the Brazilian market. The asymmetric behavior can be computed through the introduction of a disappointment (or loss) aversion coefficient in the classical expected utility function, which increases the impact of losses against gains. The results generated by both traditional and loss aversion utility functions are compared with real data from the Brazilian market regarding stock market participation in the investment portfolio of pension funds and individual investors.