Migration modelling in the New Economic Geography
Résumé
It is our aim to study some of the migration laws utilized in Economic Geography, their dynamic properties and how their long-run predictions and stability change with the specificities of the economic models under consideration. After a thorough description of Fujita and Thisse (2002), we introduce a different migration law à la Krugman (1991a). Although individuals do not foresee price changes, the steady state outcome does not vary qualitatively: the unique steady state is a symmetric distribution of skilled labour across regions. We can prove that this interior steady state is asymptotically stable, which represents a net improvement in the dynamic analysis of the long run with respect to Fujita and Thisse. When we model the economy using the Romer (1990) model applied to two regions and allowing for inter-regional skilled migration, then there exists a solution path that converges to an asymmetric steady state. In effect, the new steady state depends on technology, fixed costs, knowledge spillovers and transportation costs.