Contrary to most of the literature, which focuses only on the level of investment in innovation, this paper examines both the variety of research projects undertaken and the amount of duplication of research. A characterization of the equilibrium market portfolio of R&D projects and the socially...

We study the effect of public information on collective decision-making in a committee with members of both common and conflicting interests. We show that the set of preferences that allow for the existence of an informative voting equilibrium can be heavily restricted by the presence of a...

We introduce intention-based social preferences into a mechanism design framework with independent private values and quasilinear payoffs. For the case where the designer has no information about the intensity of social preferences, we provide conditions under which mechanisms which have been...

An auction is externality-robust if unilateral deviations from equilibrium leave the other bidders’ payoffs unaffected. The equilibrium and its outcome will then persist if certain types of externalities arise between bidders. One example are externalities due to spiteful preferences, which...

A strategy profile of a game is called robustly stochastically stable if it is stochastically stable for a given behavioral model independently of the specification of revision opportunities and tie-breaking assumptions in the dynamics. We provide a simple radius-coradius result for robust...

A nudge is a non-coercive paternalistic intervention that attempts to improve choices by manipulating the framing of a decision problem. As any paternalism, it faces the difficulty of determining the appropriate welfare criterion. We propose a welfare-theoretic foundation for nudging similar in...

In the presence of a time-inconsistency problem with optimal agency contracts, we show that competitive markets implement allocations that Pareto dominate those achieved by a benevolent planner, they induce strictly more effort, and they sometimes make the commitment problem disappear entirely....

The economic concept of the second-best involves the idea that multiple simultaneous deviations from a hypothetical first-best optimum may be optimal once the first-best itself can no longer be achieved, since one distortion may partially compensate for another. Within an evolutionary framework,...

We examine a “Rotten Kid” model (Becker 1974) where a player with social preferences interacts with an egoistic player. We assume that social preferences are intentionbased rather than outcome-based. In a very general multi-stage setting we show that any equilibrium must involve mutually...

We examine equilibria in competitive insurance markets with adverse selection when wealth differences arise endogenously from unobservable savings or labor supply decisions. The endogeneity of wealth implies that high risk individuals may ceteris paribus exhibit the lower marginal willingness to...