A practitioners' guide to gravity models of international migration

The use of bilateral data for the analysis of international migration is at the same time a blessing and a curse. It is a blessing since the dyadic dimension of the data allows researchers to analyze many previously unaddressed questions in the literature. This paper reviews some of the recent studies using this type of data in a gravity framework in order to identify important factors affecting international migration ows. Our review demonstrates that considerable efforts have been conducted by many scholars and that overall we have a much better knowledge of the relevant determinants. Still, the use of bilateral data is also a curse. The methodological challenges that are implied by the use of this type of data are numerous and our paper covers some of the most significant ones. These include sound theoretical foundations, accounting for multilateral resistance to migration as well the choice of appropriate estimation techniques dealing with the nature of the migration data and with endogeneity concerns.