Migration flows: measurement, analysis and modeling
In: White, M.J. (Ed.): International handbook of migration and population distribution, 225–241
International handbooks of population 6
Dordrecht, Springer Netherlands (2016)
The paper is an introduction to the study of migration flows. It starts with a review of major definition and measurement issues. Comparative studies of migration are particularly difficult because different countries define migration differently and measurement methods are not harmonized. Insight in data collection practices is a first requirement to study flows. In the paper, several migration indicators are presented that describe the level and direction of migration. Scientists attempt to model migration flows since Ravenstein presented his migration laws at the end of the 19th century. Initially theories and models were borrowed from physics. The gravity model, based on Newton’s law of gravitation, has been the main model of migration flows for decades and continues to be popular today. Gradually human behaviour replaced the laws of physics and spatial interaction models the gravity model. Spatial interaction models emphasize interaction between geographically dispersed populations. Initially the gravity model had a strong influence on spatial interaction models, but the interest shifted gradually to probability theory and probability models. A parallel development was the life course perspective on migration, resulting from the increased awareness that some life events trigger migration and that during some stages of life, a person has an elevated propensity to migrate. These links produce the typical and universal age patterns of migration. Today, population projection models incorporate models of these typical age patterns (model schedules) and models of spatial interaction. Projection models may be turned into policy models to infer the migration flows required to meet demographic objectives, i.e. to offset population decline resulting from low fertility.
Keywords: migration flow, models, population distribution