This paper generalizes and extends the labor market search and matching model of Berliant, Reed, and Wang (2006). In this model, the density of cities is determined endogenously, but the matching process becomes more efficient as density increases. As a result, workers become more selective in...

In this paper we develop a model of invention and knowledge-diffusion. We show, in a setting of imperfect knowledge-transfers from one generation to the next, that there is a tension between the tendency for old knowledge to be lost on the one hand, and the tendency for preserved knowledge to be...