We extend the class of quality-ladder growth models (Grossman- Helpman (1991), Segerstrom (1998) and others), to encompass an economy with asymmetric fundamentals. In contrast to the standard framework, in our model industries may di¤er in terms of their innovative potential (quality jumps and...

In an R&D-driven growth model with asymmetric fundamentals the steady state equilibrium R&D investments are industry-specific and they are such that R&D returns are equalized across industries. Return equalization, however, makes investors indifferent as to where to target research and, hence,...

This paper revisits the puzzle of immigration policy: standard economic theory predicts that free immigration improves natives' welfare, but (with few historical exceptions) an open door policy is never implemented in practice. What rationalizes the puzzle? We first review the model of...