This paper provides a view of progress over the last quarter century in the economics of international migration. I focus on two long established topics and two that have surged in the last decade. Interest in immigrant and assimilation and in the labour market effects of immigration has been kept going by methodological debates and by the diffusion of empirical work from the United States to the wider world. More recently, the difficult politics of immigration policy has fuelled the research agenda and has given rise to a new literature on the forces that drive immigration policy and on the assessment of its effects. Important also is the growth of interest in the causes and consequences of emigration from developing countries. Most notable has been the revival of interest in the brain drain and the wider consequences of the expanding emigrant diaspora.