The Global Migration Group (GMG) produced this publication to provide guidance to producers and users of international migration data. It includes detailed accounts of changes in the field of migration data, thorough explanations of key definitions and concepts, and strategies to bolster migration statistics (e.g., administrative data and 'big data'). Readers will find the notes on 'good practice' to be of particular practical value.
The report clarifies which migrants are considered "hard to count" (such as irregular migrants or trafficking victims) and offers brief overviews of methods used to measure these particular cross-border flows as well as factors influencing the data collection process. Most useful is the extensive list of sample survey questions that can be used to help identify these populations.