Revealed Deliberate Preference changes (with S. Gleyze and A. Ghersengorin) - Games and Economic Behavior - 2023
Grabbing the Fobidden Fruit (with A. Ghersengorin) - Revision invited at the Journal of Economic Behavior & Organization.
Restricting individuals' access to some opportunities may steer their desire toward their substitutes, a phenomenon known as the forbidden fruit effect. We propose and study a model named restriction-sensitive choice (RSC) that rationalizes such behaviors and that is compatible with the prominent psychological explanations: reactance theory and commodity theory. The model is identifiable from choice data, specifically from the observation of choice reversals caused by the removal of options. We give an axiomatic characterization of RSC. We conduct a normative analysis both in terms of the agent's freedom and welfare. Three applications are then analyzed. We show that our model can accommodate the backfire effect of beliefs and the backlash of integration policy targeted toward minorities. We finally study a principal's delegation problem to an agent who makes choice according to an RSC.
Description-dependent Choices (with D. Borie and D. Jullien) - Submitted
We propose a model of framing effects in which a choice reversal is due to differences in the descriptions of the same alternatives. Our contribution is to show under which conditions these framing effects can be seen as rational or not. Our results provide explanations that are aligned with existing empirical evidence not accounted for by other models and suggest experiments for further work.
Generational Equity in Democracy (with N. Colin-Jaeger) - Submitted
The aging demographic of Western democracies leaves us with an unsolved political challenge: On the one hand, older voters are more in number and tend to participate more, transforming the political process to their advantage; on the other hand, democratic equality seems to imply the "one person, one vote", which renders infeasible any possibility to change this situation. This article offers a twofold contribution: first, it shows on what ground age-weighted voting is normatively appealing when considering the possibility of wrongful intergenerational exploitation; second, it proposes a voting rule correcting for demographic unbalance and participation differential, capturing the essence of the normative claim, and shows what effects such a rule would have on the electoral competition.
Comparisons for the Lesser Harm (with Y. Breitmoser)
We propose a new ordinal axiom to address the problem of interpersonal comparisons, which we call the Agreement Principle. The axiom says the following: if two individuals both agree that the worse-off person in one efficient allocation is better off than the worse-off person in another efficient allocation, then a social planner should prefer the first allocation. We show that any social preference satisfying this principle can be represented by what we call a Multi-Pareto-spined metric. In this representation, the welfare of each individual is given by the sum of two continuous and increasing indices. One index reflects that individual’s own preferences, and the other reflects the perspective of the other individual. For every Pareto-optimal allocation, these indices agree on how well each person is doing, ensuring consistency across the different viewpoints. We then explore the relationship between this representation and the concept of envy-freedom, and we identify conditions under which the two coincide. After presenting some illustrative examples, we conclude by discussing several possible extensions of the framework.
Note on the indeterminacy of reveled deliberate preference changes (with A. Ghersengorin)
In a companion paper (Boissonnet, Ghersengorin, and Gleyze, 2022), we develop a model of rational preference change that is both axiomatically grounded and empirically testable. To achieve this, we restrict our focus to a specific class of preference changes—those we call deliberate preference changes. These are changes initiated by the decision maker (DM) herself after becoming aware of new values, reasons, or dimensions of the choice environment. The primitives of the model consist of a sequence of preference orderings over a fixed set of options, together with the attributes characterizing these options. Our axioms build on a key object that can be inferred from these primitives: the sequence of revealed relevant attributes. BGG shows that the DM’s successive preference changes can be represented as if she were genuinely relying on the revealed relevant attributes both when making choices at each period and when revising her preferences between periods.A violation of the axioms may indicate that the revealed relevant attributes do not correspond to the DM’s actual relevant attributes—in which case her behavior may still fit the general structure of our model, but only under a different sequence of relevant attributes. As a result, BGG leaves unresolved a problem of indeterminacy. In this note, we clarify the nature of this indeterminacy and provide axioms that characterize a more general version of deliberate preference change.
Rationalizing preference formation by partial deliberation
In this paper, I propose to model a mechanism through which preference changes are due to awareness changes; a mechanism that I refer to as partial deliberation. With partial deliberation, the DM chooses the system of values that determines her preferences by maximizing an axiological criterion. But her ability to do so is constrained by her awareness. This mechanism is worth studying because it has two interesting properties. First, it implies that the background values of the DM influence the way the DM chooses to change her preferences. Second, it implies that a DM becoming aware simultaneously of values does not end up with the same preference change as DM that becomes aware sequentially of new values. I study this mechanism to answer three issues. First, I show that this mechanism does not lead to ad hoc explanations, since it can rule out some preference changes, making them inconsistent. To show that, I provide axiomatic foundations for this mechanism. Second, I study more constraining version of partial deliberation to see how they constrain choice. Third, I show that this mechanism can be applied to capture the endowment effect and some aspect of habit formation.
Welfare maximization under risk and uncertainty without homogeneity, convexity, and divisibility (Joint work with Y. Breitmoser)
We consider welfare maximization under risk in a general framework without divisibility, convexity and homogeneity. We characterize and index the set of Pareto-efficient, envy-free (Peef) allocations as well as corresponding welfare functions. In the $n$-agent economy, each allocation is indexed by an $n$ dimensional vector characterizing the agents' surpluses subject to being Peef. Each such allocation maximizes a welfare function that is a weighted sum of $n$ so-called contract curve equivalents. Each contract curve equivalent evaluates an allocation to agent $j$ based on a projection of the contract curve to allocations for a agent $i$, which the welfare function additively aggregates over all contract curve projections $i$, and then max-min aggregates over all agents $j$. We show that an allocation is Peef if and only if it has a representation based on such a welfare function, which contains many prior results such as certainty equivalents, lottery equivalents, and equally distributed equivalents as special cases relating to contract curve projections under particular conditions. We also demonstrate the robustness of the results to ambiguity.
Domain restriction and pluralism in a representative democracy (Joint work with N. Colin-Jaeger)
Relaxing the universal domain axiom has often been proposed to solve the Arrow's impossibility theorem (see Black, 1951; Inada, 1969; Sen and Pattanaik, 1969). Along this line, economists have proposed to characterize the kind of restrictions to the domain of preference profiles such that there exists a welfare social function generating a choice function. From a political philosophy perspective, this discussion is relevant to the debate over the extent of pluralism (see List, 2011). In this approach, these restrictions are independent of the implemented voting rule (majority, unanimity, etc.). Yet, in a representative democracy, a voting system induces political games (e.g., formation of a coalition, deliberation, etc.) that ultimately shapes voters' preferences profiles. Consequently, the domain of preferences profile may be universal ex-ante but restricted by the electoral political game ex-post, and a voting rule may be perfectly pluralistic alone---no domain restriction---but restricted when induced by its political game. We can thus distinguish ex-ante pluralism from ex-post pluralism. In this paper, we study the effect of an ``electoral political game'' in which preferences profiles are induced by a coalition formation process (i.e. party formation), and which outcome is a set of candidates (coalition) contingent on the implemented voting rule. We start with a set of political issues (i.e., free markets/ protectionism, restriction on immigration/ open borders, feminism/ conservatism, etc.) defined with various intensities. A political project is a vector with the vehemence of political issues as coordinates, and voters' have fixed (quadratic) preferences over political projects. There is a (finite) set of potential candidates with various political preferences (drawn from a random distribution). The candidates have imperfect but public information on the voters' preferences (e.g., polls, surveys). Potential candidates can bargain to form a joint political program (i.e., a political project). When they do, they form a coalition. To model the outcome of bargaining, we use a generalization of the Nash bargaining approach, in which the disagreement points depend on the result of the electoral competition. Although Elster (1986) distinguishes deliberation from negotiation, this bargaining process can be interpreted as a weak form of deliberation over people's will. This coalition formation process results in effective candidates and election winners. Crucially, these outcomes depend on the voting rules. Each voting rule induces a set of effective coalitions. Hence, we can check for various voting rules whether Pattanaik and Sen's conditions on preferences profiles are satisfied for its induced effective alliances. Therefore, we can compare different classical voting rules according to their consequences for ex-ante and ex-post pluralism.
The state as a family and its dynamics: effect analogical reasoning between family strcture and political instituions (Joint work with T. Verdier)
Les cinq affirmations de la délibération partielle (french version)
Economists have been less and less reluctant to include endogenous preferences in there models. However, there is a lack of general models that describe the psychological process behind preferences changes. This paper constitutes a first step toward a theory that fulfills this gap. It presents a conceptual analysis of a specific mechanism, in which preferences are awareness driven that is, they are formed through a process of partial deliberation on the values that induce them. The paper is compounded of five sections, each of them presenting and justifying the hypothesis required for this mechanism. According to the first hypothesis preferences are induced by values. According to the second, these values can be logically connected so that they form systems, that can be hierarchically ordered by a consistency criterion. The third hypothesis is that agents can have a partial representation of the values that induces their preferences. In other words, the agent is aware of only a limited set of the values that induces his preferences, value in this set are called reasons to act. With fourth hypothesis the agent can change the reasons that induces his behavior. With the fifth hypothesis, we argue that agents do change their reasons to act by using the consistency criterion of the second hypothesis. To conclude I argue that the process of partial deliberation allows to extend the concept of rationality to the concept of autonomy.
A theory of preferences manipulation
A sender often tries to figure out how a receiver's preferences change in order to propose him a project that best fits both of their preferences. In parallel she may try to change the preference of the receiver. This paper models such situations by using an euclidean approach of \textit{partial deliberation}, a mechanism in which preference changes are yielded by changes in the awareness of the receiver. Thus, the sender must choose a project and a disclosure strategy. I show how the set theoretic approach of partial deliberation can be adapted to an euclidean one, in which the receiver modifies the intensity she assigns to values. In this paper, I show that the axiological criterion used by the sender to change her value system can be represented by a function Φ that maps each vector v into R. Then I apply this new conceptual framework to formalize imperfect empathy, i.e., a situation in which the sender is uncertain about what determine the receiver's preferences. I also study situations in which the sender tries to use sequential disclosure strategy rather than a simultaneous one.
Should government make thwarted attacks public? A theoretical approach (joint work with Antoine Pietri)
We design a signaling game in which a government (the sender) detains information about the level of thwarted terrorist attacks unobserved by the population (the receiver). A signal is a public statement in which the government states the existence of an unobserved threat, or not. The government manipulates posterior beliefs of the population to trigger its best reaction in order to avoid future attacks. Indeed, on the one hand, a low level of awareness of terrorist threat may lower the effectiveness of counter-terrorist actions. On the other hand, an exaggerate panic may also be counter-productive. That is why a benevolent government may have interest to lie about the threat that is not observed by the population. Our main results may be summarized as follows. First, our model shows that the government does not make public a thwarted attack if there is no threat initially observed by the population, or if the signal is ineffective. Second, when the credibility of the signal is sufficiently low, we find that the government always reveals the true state of the threat. However, if the signal has an important impact on the posterior belief of the population (i.e. credible signal), then the government may have an interest to lie for intermediate levels of terrorist threat: either announcing a thwarted attack that did not happen, or hiding a thwarted attack that really happened. It should be noticed that for extreme situations (very high or low levels of threat), the government never lies to the population.
The dynamics of cultural mixing
When looking at cultural evolution as a transmission mechanism the question of the the preservation of heterogeneity in cultural attributes (for subsequent generations) becomes of paramount importance. Models that incorporate such heterogeneity currently focus on a preference-based opposition between cultural traits (Bisin and Verdier, 2001; Benabou Tirole 2006). The parameters of the individuals’ utility functions used in these models and the shape of the functions themselves clearly reflect this opposition between cultural traits. Furthermore, it is the modeler who decides which is the relevant opposition to focus on, and the cultural dynamics are usually constrained by the extreme points of this opposition. The formation of new cultural traits is not considered. In this paper, we propose a complementary approach where the dynamics of cultural transmission are based on a principle of compatibility between cultures: cultural transmission is possible only for “mixable cultures”, while cultures that contradict each other cannot be mixed. This particular strategy allows for the building of a dynamic model in which new cultural traits can emerge. We characterize a given cultural trait by a two-valued function or “meaning function ” that represents the relation that individuals make between cultural symbols like words, sentences, gestures or signs. This formulation of the problem makes it possible to define the opposition of the meaning function through the product of two functions: the first function would negatively relate the two cultural symbols, while the second function would relate them positively. Two cultural traits are (said to be) “opposed” if they are globally opposed in their meaning function. The concept of a “mixable cultural trait” allows us to produce a graph in which the nodes represent the individuals. The neighbors of each individual represent other individuals with whom a node can be mixed. By considering only the neighborhood that individuals (maximally) choose to modify their meaning function and therefore to modify their cultural trait. We show the convergence of this algorithmic process and study applied situations.