This paper studies a model of human capital accumulation with real wage rigidity. It is shown that the arbitrage condition between hiring a skilled versus an unskilled worker may be stated as a positive relationship between their relative unemployment rates. It may be the case that this locus is...

We study the incentives to improve ability in a model where heterogeneous firms and workers interact in a labor market characterized by matching frictions and costly screening. When effort in improving ability raises both the mean and the variance of the resulting ability distribution, multiple...

This Paper develops a model for analysing the costs and benefits of intellectual property enforcement in LDCs. The North is more productive than the South and is the only source of innovator. There are two types of goods, and each bloc has a comparative advantage in producing a specific type of...

How can we explain the success of cooperative networks of firms that share innovations, such as Silicon Valley or the Open Source community? This Paper shows that if innovations are cumulative, making an invention publicly available to a network of firms may be valuable if the firm expects to...