We use a simple graphical approach to represent Social Welfare Functions that satisfy Independence of Irrelevant Alternatives and Anonymity. This approach allows us to provide simple and illustrative proofs of May's Theorem, of variants of classic impossibility results, and of a recent result on...

We propose a criterion of approximate incentive compatibility, strategy-proofness in the large (SP-L), and argue that it is a useful second-best to exact strategy-proofness (SP) for market design. Conceptually, SP-L requires that an agent who regards a mechanism's “prices” as exogenous to...

Some public goods are provided entirely with private contributions, others with a mixture of public and private funding, and still others are entirely publicly funded. To explain this variation, a model of dual provision is developed that endogenizes public and private funding. Members of the...

We study a dynamic model of environmental protection in which the level of pollution is a state variable that strategically links policy making periods. Policymakers are forward looking but politically motivated: they have heterogeneous preferences and do not fully internalize the cost of...

This paper reviews the literature on governments' motivations for negotiating and joining international trade agreements. I discuss both normative explanations for trade agreements and explanations based on political-economy concerns. Most of the paper focuses on the purpose of multilateral...

I study expertise acquisition in a model of trading under asymmetric information. I propose and implement a method to estimate the ratio of social to private marginal value of expertise. This can be decomposed into three sufficient statistics: traders' average profits, the fraction of bad assets...

We model visibility bias in the social transmission of consumption behavior. When consumption is more salient than non-consumption, people perceive that others are consuming heavily, and infer that future prospects are favorable. This increases aggregate consumption in a positive feedback loop....

The public at large, many policymakers, and some economists hold views of social welfare that attach some importance to factors other than individuals' utilities. This note shows that any such non-individualistic notion of social welfare conflicts with the Pareto principle

In this paper, we propose a new measure of horizontal equity that overcomes many of the shortcomings of previous proposed measures. Our starting point is the observation that a well-behaved social welfare function need not evaluate global' (vertical equity) differences in after-tax income using...