Cross-national comparisons of internal migration remain an embryonic and challenging
field of inquiry. Compared with other areas of demography, particularly fertility and
mortality, there is no single repository of data capturing mobility within countries, and
comparisons are hindered by widespread variation in data collection practices. These include
differences in the types of data collected (e.g. events versus transitions), the intervals over
which migration is measured (e.g. one year, five years, since birth, or latest move regardless
of the timing), and the statistical geography over which migration is defined. Over the past
decade, there have been a number of concerted attempts to address these issues. Bell and
others (2002), surveyed key issues hampering cross-national comparisons of internal
migration and proposed a series of indicators, which could provide a basis for such
comparisons. Bell and Muhidin (2009), subsequently utilised a number of these metrics to
estimate the intensity, age patterns, and spatial impacts of internal migration for 28 countries.
A large-scale international research project, Comparing Internal Migration Around the
GlobeE (IMAGE), is currently extending this work to cover a majority of the 193 United
Nations Member States. While final results will take some time, it is useful to provide
progressive updates on the task of drawing together rigorous comparisons. Accordingly, this
paper has been assembled to summarise progress on the IMAGE project and the current state
of knowledge on global trends in internal migration. The paper updates and extends the
analysis undertaken for the United Nations Development Programme by Bell and Muhidin in
2009, and has been formulated principally to provide input to the forty-sixth session of the
Commission on Population and Development, on the theme New Trends in Migration:
Demographic Aspects.