Evolving networks of inventors

In this paper we develop a model of R&D alliance formation. Pairs of firms combine their knowledge in an attempt to innovate. Whether this attempt is successful depends in part on whether the pair has been successful in the past: accumulated experience teaches a pair of firms how to innovate together, but at the same time increases the similarity of their knowledge stocks. A tension exists between the desire for a familiar partner, and desire for a partner with complementary knowledge. How this tension is resolved depends on the nature of the innovation process itself, and the elasticity of substitution of different types of knowledge inputs in knowledge production. From the alliance-innovation process, a variety of networks form. In different parts of the parameter space we observe isolated agents, a dense, connected network, and small worlds.     

International Trade and Unemployment—the Worker‐selection Effect

This paper investigates the labor market effects of trade liberalization. We incorporate trade unions and heterogeneous workers into the Melitz framework. Workers differ with respect to their abilities. Our main findings are: (i) trade liberalization harms low‐ability workers, they lose their job and switch to long‐term unemployment (worker‐selection effect); (ii) high‐ability workers are better off in terms of both higher wages and higher employment; (iii) if a country is endowed with a large fraction of low‐ability workers, trade liberalization leads to a rise in aggregate unemployment—in this case, trade liberalization may harm a country's welfare; (iv) the overall employment and welfare effect crucially hinges on the characteristics of the wage bargain.     

Trade Sanctions and the Incidence of Child Labor

The purpose of this paper is to develop an imperfect competition model of a small open developing country to analyze the effects of trade sanctions on the incidence of child labor. We show that a uniform tariff levied by the developed countries on imports produced with the help of child labor is a failure in terms of reducing child labor. A more effective course of action would be a firm‐specific tariff where the tariff rate varies with the amount of child labor incorporated in a single good. While such an instrument reduces child labor, however, it worsens the children’s well‐being due to lower income and consumption. Contrary to expectations, the entrepreneurs in the developing countries, supposedly the main beneficiaries of child labor, are better off under trade sanctions as they realize higher profits.