Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Measuring the extent and direction of the movement of people across space is key to understanding spatial gaps and processes of structural transformation. A range of sources from census data, survey data, to administrative data and newer types of data such as mobile phone data have been used to examine such patterns. This paper investigates how different types of data are used to measure migration and mobility, and how complementary data determine which research questions they can answer. I discuss measurement concerns related to these different types of data, definitions of migration rates used in the literature, selection concerns and other survey design considerations. I conclude by highlighting gaps in the measurement of migration.