This paper studies how an institution such as markets affects the evolution of mankind. My key point is that the forces of natural selection are made weaker because trade allows people to specialize in those activities where they are strong, and to offset their weaknesses by purchasing adequate...

This paper studies aggregate dynamics in a cobweb model where learning takes place through a selection mechanism, by which more successful firms are replicated at a higher rate. The structure of the model allows to characterize analytically the aggregate dynamics, and to compute the effect on...

In order to credibly "sell" legitimate children to their spouse, women must forego more attractive mating opportunities. This paper derives the implications of this observation for the pattern of matching in marriage markets, the dynamics of human capital accumulation, and the evolution of the...

Much of the political economy analysis of reform focuses on the conflict of interest between groups that stand to gain or lose from the competing policy proposals. In reality, there is also a lot of disagreement about the working of the policy: in addition to conflicting interests, conflicting...

This paper provides some elements to explain the observed takeover in some urban areas of a new kind of elite associated with new economy jobs, also known as "bourgeois bohème" (bobos). This takeover has been associated with greater investment in urban amenities and "clean" means of transport,...

We study active labor market policies (ALMP) in a matching model. ALMPs are modelled as a subsidy to job search. Workers differ in their productivity, and search takes place along an extensive margin. An additional job seeker affects the quality of unemployed workers. As a result, the Hosios...

When policymakers and private agents use models, the economists who design the model have an incentive to alter it in order to influence outcomes in a fashion consistent with their own preferences. I discuss some consequences of the existence of such ideological bias. In particular, I analyze...

Economists traditionally tackle normative problems by computing optimal policy, i.e. the one that maximizes a social welfare function. In practice, however, a succession of marginal changes to a limited number of policy instruments are implemented, until no further improvement is feasible. I...

This paper analyses the economic issues associated with human cloning and new reproductive technologies. We analyze the incentives for human cloning and its implications for the long run distribution of skills and income. We analyse models of human cloning for different motives, focusing on...

This paper analyses the welfare effects of price restrictions on private contracting in a world where agents have a limited cognitive ability. People compute the costs and benefits of entering a transaction with an error. The government knows the distribution of true costs and benefits as well...