Thomas Demuynck

Nash rationalization of collective choice over lotteries

To test the joint hypothesis that players in a noncooperative game (allowing mixtures over pure strategies) consult an independent preference relation and select a Nash equilibrium, it suffices to study the reaction of the revealed collective choice upon changes in the space of strategies available to the players. The joint hypothesis is supported if the revealed choices satisfy an extended version of Richters congruence axiom together with a contraction-expansion axiom that models the noncooperative behavior. In addition, we provide sufficient and necessary conditions for a binary relation to have an independent ordering extension, and for individual choices over lotteries to be rationalizable by an independent preference relation.

Revealed Preference Analysis of Non‐Cooperative Household Consumption

We develop a revealed preference approach to analyse non-unitary household consumption behaviour that is not cooperative (or Pareto efficient). We derive global necessary and sufficient conditions for data consistency with the model. We show that the conditions can be verified by means of relatively straightforward mixed integer programming methods, which is particularly attractive in view of empirical analysis. Our framework extends to tests for separate spheres and joint contribution to public goods. An application to data drawn from the Russia Longitudinal Monitoring Survey demonstrates the empirical relevance of the non-cooperative consumption model.

A general extension result with applications to convexity, homotheticity and monotonicity

A well-known result in the theory of binary relations states that a binary relation has a complete and transitive extension if and only if it is consistent ([Suzumura K., 1976. Remarks on the theory of collective choice, Economica 43, 381-390], Theorem 3). A relation is consistent if the elements in the transitive closure are not in the inverse of the asymmetric part. We generalize this result by replacing the transitive closure with a more general function. Using this result, we set up a procedure which leads to existence results for complete extensions satisfying various additional properties. We demonstrate the usefulness of this procedure by applying it to the properties of convexity, homotheticity and monotonicity.

I'll Never Forget My First Cigarette: A Revealed Preference Analysis of the 'Habits as Durables' Model

We provide a revealed preference analysis of the “habits as durables” model. This approach avoids the need to impose a functional form on the underlying utility function. We show that our characterization is testable by means of linear programming methods, and we demonstrate its practical usefulness by means of an application to cigarette consumption using a Spanish household consumption data set. We find that the “habits as durables” model has better empirical fit in terms of predictive success compared to the “short memory habits” and life cycle models.

Inequality Adjusted Income Growth

We introduce and characterize a new measure of aggregate income growth that allows us to give more weight to individuals with lower individual income growth. Our measure includes several important measures of directional mobility encountered in the literature. The empirical application compares the measure of income growth between the USA and Germany, and finds that giving more weight to individuals with lower income growth reverses the ranking.

Revealed Preference Theory for Finite Choice Sets

The theory of revealed preferences offers an elegant way to test the neoclassical model of utility maximization subject to a linear budget constraint. In many settings, however, the set of available consumption bundles does not take the form of a linear budget set. In this paper, we adjust the theory of revealed preferences to handle situations where the set of feasible bundles is finite. Such situations occur frequently in many real life and experimental settings. We derive the revealed preference conditions for consistency with utility maximization in this finite choice set setting. Interestingly, we find that it is necessary to make a distinction between the cases where the underlying utility function is weakly monotone, strongly monotone and/or concave. Next, we provide conditions on the structure of the finite choice sets for which the usual revealed preference condition (i.e. GARP) is still valid. We illustrate the relevance of our results by means of an illustration based on two experimental data sets that contain choice behaviour from children and young adults. Copyright Springer-Verlag Berlin Heidelberg 2015 (This abstract was borrowed from another version of this item.)

Noncooperative Household Consumption with Caring

We present a household consumption model that accounts for caring household members, while allowing for noncooperative behavior in decisions on public goods. The intrahousehold consumption outcome critically depends on the degree of caring between the household members. By varying the degree of intrahousehold caring, the model encompasses a whole continuum of household consumption models that are situated between the fully cooperative model and the noncooperative model without caring. This feature is used to define a measure for the degree of cooperation within the household. We also establish a dual characterization of our noncooperative model with caring preferences: we show that the model is dually equivalent to a noncooperative model with non-caring preferences that is characterized by intrahousehold transfers. Finally, following a revealed preference approach, we derive testable implications of the model for empirical data. We demonstrate the practical usefulness of the model through an illustrative application.

Nonparametric Welfare and Demand Analysis with Unobserved Individual Heterogeneity

This paper combines revealed preference and nonparametric estimation techniques to obtain nonparametric bounds on the distribution of the money metric utility and demand functions over a population of heterogeneous households. Our approach is independent of any functional specification on the household utility functions. Our method applies the weak axiom of revealed preference to a population of heterogeneous households. Although this does not produce the sharpest bounds, we show that it is computationally attractive and provides narrow bounds. We demonstrate the usefulness of our results by applying it to the Consumer Expenditure Survey, a U.S. cross–sectional consumption data set.

Group Consumption with Caring Individuals

We propose a novel approach to model joint consumption decisions of individuals who care for each other. We assume noncooperative interaction between the different individuals and the within-group consumption outcome critically depends on the degree of caring between the group members. By varying the degree of caring, the model encompasses a whole continuum of group consumption models that are situated between the fully cooperative model (assuming a Pareto optimal outcome) and the noncooperative model without caring (assuming a public good game with voluntary contributions). This feature is used to define a measure for the degree of cooperation within the group, which quantifies how close the observed group behavior is to the fully cooperative benchmark. We also establish a dual characterization of our noncooperative model with caring preferences: we show that the model is dually equivalent to a noncooperative model with non-caring preferences that is characterized by intra-group transfers. Following a revealed preference approach, we derive testable implications of the model for empirical data. Finally, we also use our model to analyze decisions made by dyads of children in an experimental setting. We find considerable heterogeneity in the degree of caring (or cooperation) across dyads, which correlates with assertiveness and the degree of interaction within dyads.