Migrations have occurred throughout human history. Today, people inhabit virtually every corner of the world. In fact, given the upsurge in the last few decades, more people are on the move today than at any other point in time. In order to get an understanding of the driving forces shaping migration patterns across countries and within destinations, this dissertation investigates the determinants of bilateral international migration and the location choice of immigrants with particular attention to a number of methodological challenges and for various geographical regions, i.e. migration to the OECD, migration between SSA countries and immigrants’ location choice in Belgium. Specifically, the first chapter presents an overview of the most important migration theories, the stance of the recent empirical literature and methodological issues that arise. It elucidates also how the following empirical chapters address some of these methodological issues as well as how they contribute to the literature. The second chapter investigates the determinants of bilateral immigrant flows to 19 OECD countries between 1998 and 2007 from both advanced and developing origin countries. It pays particular attention to dynamics by including both the lagged migrant flow and the migrant stock to capture partial adjustment and network effects. To correct for the dynamic panel data bias of the fixed effects estimator a bootstrap algorithm is used. The results indicate that immigrants are primarily attracted by better income opportunities and higher growth rates abroad. Also short-run increases in the host country’s employment rate positively affect migration from both advanced and developing countries. High public services, on the other hand, discourage migration from advanced countries but exert a pull on migration from developing sources, in line with the welfare state hypothesis. Finally, there is evidence for both partial adjustment and the presence of strong network effects. This confirms that both should be considered crucial ...