Rational preferences under ambiguity

This paper analyzes preferences in the presence of ambiguity that are rational in the sense of satisfying the classical ordering condition as well as monotonicity. Under technical conditions that are natural in an Anscombe?CAumann environment, we show that even for such a general preference model, it is possible to identify a set of priors, as first envisioned by Ellsberg (Q J Econ 75:643?C669, 1961). We then discuss ambiguity attitudes, as well as unambiguous acts and events, for the class of rational preferences we consider.     

Cobb-Douglas preferences under uncertainty

This paper axiomatizes Cobb-Douglas preferences under uncertainty. First, we extend the original Trockel (Econ Lett 30:7–10, 1989)’s axiomatic foundation to a general state space framework based on the Strong Homotheticity Axiom, obtaining also the incomplete case a la Bewley (Decis Econ Financ 25:79–110, 2002). We show that this key axiom for the Cobb-Douglas expected utility specification is refuted by Ellsberg’s uncertainty aversion behavioral pattern. Our main result provides a set of meaningful axioms characterizing Cobb-Douglas min-expected utility preferences, an important class of uncertainty averse preferences for studying the consequences of ambiguity in finance and other fields. Finally, we present briefly how to obtain more general representations like the variational case.     

Multiproduct tariffs

Necessary conditions characterizing optimal nonlinear multiproduct tariffs are derived from aggregate data about customers' responses to linear tariffs. These conditions are amenable to numerical solution with standard software by using a discrete formulation of an associated nonlinear optimization problem cast in terms of the marginal prices charged for incremental bundles. This approach avoids integrability restrictions that otherwise encumber the computations. However, this method does not ensure that customers' second-order conditions for optimality of their demands are satisfied. Some numerical examples are provided, and the extension of the method to Ramsey pricing is also demonstrated.     

Collective choice under dichotomous preferences

Agents partition deterministic outcomes into good or bad. A mechanism selects a lottery over outcomes (time-shares). The probability of a good outcome is the canonical utility. The utilitarian mechanism averages over outcomes with largest “approval”. It is efficient, strategyproof, anonymous and neutral.We reach an impossibility if, in addition, each agent's utility is at least , where n is the number of agents; or is at least the fraction of good to feasible outcomes. We conjecture that no ex ante efficient and strategyproof mechanism guarantees a strictly positive utility to all agents, and prove a weaker statement.     

Risk preferences under acute stress

Many important decisions are made under stress and they often involve risky alternatives. There has been ample evidence that stress influences decision making, but still very little is known about whether individual attitudes to risk change with exposure to acute stress. To directly evaluate the causal effect of psychosocial stress on risk attitudes, we adopt an experimental approach in which we randomly expose participants to a stressor in the form of a standard laboratory stress-induction procedure: the Trier Social Stress Test for Groups. Risk preferences are elicited using a multiple price list format that has been previously shown to predict risk-oriented behavior out of the laboratory. Using three different measures (salivary cortisol levels, heart rate and multidimensional mood questionnaire scores), we show that stress was successfully induced on the treatment group. Our main result is that for men, the exposure to a stressor (intention-to-treat effect, ITT) and the exogenously induced psychosocial stress (the average treatment effect on the treated, ATT) significantly increase risk aversion when controlling for their personal characteristics. The estimated treatment difference in certainty equivalents is equivalent to 69 % (ITT) and 89 % (ATT) of the gender-difference in the control group. The effect on women goes in the same direction, but is weaker and insignificant.     

Multiple equilibrium under CES preferences

Under the simplifying assumptions that (1) there are two commodities and two agents, (2) production (endowment) of each commodity per period is fixed, (3) preferences of the two agents are of CES type, and (4) both the endowments and the CES preferences are mirror images of each other (called “supersymmetry”), it is shown that (a) there always exists a symmetric equilibrium with a unit price ratio, (b) a sufficient condition for the stability (hence uniqueness) of this symmetric equilibrium is that the elasticity of substitution satisfy ${\sigma\geqq 1/2}$ , and (c) multiple (triple) equilibrium is possible if and only if each agent has a relative preference for the good that is sold (“exported”) to the other agent. Further conditions for multiple equilibrium are derived.     

PV adoption: the role of distribution tariffs under net metering

Journal of Regulatory Economics - The deployment of decentralized productions units (DPU) like rooftop solar panels is a major challenge for a transition towards greener energy sources. Under a net...     

Welfare‐ranking ad valorem and specific tariffs under monopolistic competition

Abstract.  Actual trade and tariff policy prefers ad valorem tariffs to specific tariffs. Yet in this paper we show that, in a setting of monopolistic competition, realizing a given restriction on imports via a specific tariff would generate more consumer utility than obtaining the same restriction via an ad valorem tariff. JEL classification: F12     

On tariffs and smuggling

The purpose of this paper is to show that if a country wants to eliminate smuggling, it may have to increase rather than decrease the tariff. This paradoxical case could take place if the country in question is large and the foreign elasticity of demand for imports is inelastic.     

Representation and aggregation of preferences under uncertainty

We axiomatize in the Anscombe-Aumann setting a wide class of preferences called rank-dependent additive preferences that includes most known models of decision under uncertainty as well as state dependent versions of these models. We prove that aggregation is possible and necessarily linear if and only if (society's) preferences are uncertainty neutral. The latter means that society cannot have a non-neutral attitude toward uncertainty on a subclass of acts. A corollary to our theorem is that it is not possible to aggregate multiple prior agents, even when they all have the same set of priors. A number of ways to restore the possibility of aggregation are then discussed.     

Environmental tariffs on polluting imports

This paper examines the implications for the use of trade measures as weapons to address global environmental concerns. There are already proposals in the U.S. senate to impose an environmental tariff against foreign nations whose cost advantages stem from less stringent environmental standards than the U.S. The paper argues that trade policy measures typically are not the first best instruments for achieving environmental objectives. Even theoretically they could be shown to be welfare improving only under a very narrow range of circumstances. Their use in place of more efficient policy instruments may not only end up distorting the patterns of world trade but also may worsen the overall patterns of environmental quality. Simulation exercises undertaken here suggest that it is highly unlikely that countries would alter their environmental behavior because of the imposition of the proposed U.S. tariff. Hence the proposed legislation has very uncertain environmental consequences. Even if the policy has been mainly designed to protect domestic industries, it would only provide a minor margin of protection because the costs of complying with the environmental standards represent a relatively small element in the total costs. The analysis suggests that trade policy introduced in this fashion will have no significant impact on the patterns of world trade and pollution.     

A welfare analysis of tariffs and equivalent quotas under demand uncertainty: Implications for tariffication

Under market demand uncertainty, we show that quotas can result in a welfare advantage over tariffs for an importing country despite that its government does not capture any quota rents. Specifically, the conditions under which an equivalent quota yields higher expected welfare than a tariff are shown to depend on a set of economic variables. These variables include the initial tariff rate, the relative efficiency in production between home and foreign firms, the probability distribution of random demand shocks that make the quota binding or non-binding under uncertainty, as well as the variance of the stochastic market demand. The analysis of this paper has welfare implications for tariffication.     

Public goods and optimal paternalism under present-biased preferences

This paper concerns the provision of a state-variable public good in a two-type model under present-biased consumer preferences. The preference for immediate gratification facing the high-ability type weakens the incentive to adjust public provision in response to the self-selection constraint.     

Efficient and stable collective choices under gregarious preferences

We consider collective choice problems where a set of agents have to choose an alternative from a finite set and agents may or may not become users of the chosen alternative. An allocation is a pair given by the chosen alternative and the set of its users. Agents have gregarious preferences over allocations: given an allocation, they prefer that the set of users becomes larger. We require that the final allocation be efficient and stable (no agent can be forced to be a user and no agent who wants to be a user can be excluded). We propose a two-stage sequential mechanism whose unique subgame perfect equilibrium outcome is an efficient and stable allocation which also satisfies a maximal participation property.     

Singleton bias and lexicographic preferences among equally valued alternatives

Two experiments examined a form of singleton bias deducible from lexicographic choice and Tversky’s theory of elimination by aspects. In Experiment 1, 100 decision makers who chose from a set of job applicants defined by equal numbers of equally important qualifications tended to ignore the singleton defined by possession of a relevant attribute but tended to rank-order the attributes as predicted by lexicographic choice theory and showed various forms of singleton bias. In Experiment 2, 100 decision makers who chose from sets of unspecified alternatives, universities, and houses/apartments defined by attributes that they had individually rated as equally important ignored the attribute-defined singleton in every alternative set but manifested a different singleton bias in favor of the middle option of the on-screen display.     

An indistinguishability result on rationalizability under general preferences

In this paper, we show that, in the class of games where each player??s strategy space is compact Hausdorff and each player??s payoff function is continuous and ??concave-like,?? rationalizability in a variety of general preference models yields the unique set of outcomes of iterated strict dominance. The result implies that rationalizable strategic behavior in these preference models is observationally indistinguishable from that in the subjective expected utility model, in this class of games. Our indistinguishability result can be applied not only to mixed extensions of finite games, but also to other important applications in economics, for example, the Cournot?Coligopoly model.     

The structure of Nash equilibrium tariffs

This paper examines theoretically the structure of optimal (Nash equilibrium) tariff rates in a two-country economy with more than two traded goods. We provide a condition under which the equilibrium tariff rates are uniform in both countries, and explore the relative size of the equilibrium tariff rates in each country when the uniform tariff condition is not satisfied. The elasticities of compensated excess demand for goods play an important role in characterizing the structure of the equilibrium tariff rates. This paper undertakes the analysis using a dual approach.