We test the hypothesis that "genuine" or "convincing" smiling is a costly signal that has evolved to induce cooperation in situations requiring mutual trust. Potential trustees in a trust game made video clips for viewing by potential trusters before the latter decided whether to send them...

This paper quantifies the relationship between market size and innovation in the pharmaceutical industry using improved, and newer, methods and data. We find positive significant elasticities of innovation to expected market size with a point estimate under our preferred specification of 0.23....

This paper explains the multiple adoption of agriculture around ten thousand years ago, in spite of the fact that the …first farmers suffered worse health and nutrition than their hunter gatherer predecessors. If output is harder for farmers to defend, adoption may entail increased defense...

While vertical integration is traditionally seen as a solution to the hold-up problem, this paper highlights instead that it can generate hold-up problems — for rivals. We first consider a successive duopoly where competition among suppliers eliminates any risk of hold-up; downstreamfirms thus...

We examine the impact of the licensing policies of one or more upstream owners of essential intellectual property (IP hereafter) on the variety offered by a downstream industry, as well as on consumers and social welfare. When an upstream monopoly owner of essential IP increases the number of...

We study how career concerns affect the dynamics of incentives in a multi-period contract, when the agent’s productivity can evolve exogenously (random shocks) or improve endogenously through investment. We show that incentives are stronger and performance is higher when the contract...

We develop an agency model of organized crime accounting for the main trade-offs involved by the introduction of an accomplice-witness program. We characterize the optimal policy and identify its main determinants in a framework where public officials can be dishonest. Our predictions are tested...

This paper analyzes competitive pricing policies by multiproduct firms facing heterogeneous buying patterns. We show that cross-subsidization arises when firms have comparative advantages on different products but are equally efficient overall: Firms earn a profit from multi-stop shoppers by...

We develop a model of interlocking bilateral relationships between upstream firms (manufacturers) that produce differentiated goods and downstream firms (retailers) that compete imperfectly for consumers. Contract offers and acceptance decisions are private information to the contracting...