An extensive empirical literature indicates that, even without formal intellectual property rights, innovators enjoy a variety of first-mover advantages and that `imitation' is itself a costly activity. There is also accumulating evidence that an `open' approach to knowledge production can...

The aim of this paper is to develop a spatial model that explicitly incorporates the different types of knowledge spillovers taking place in cities and to show how they affect the migration decision of individuals and the size of cities. We use a static general equilibrium framework with two...