Data

Migration seems set to keep rising as a prominent global issue but research and policy-making in the field clearly suffer from a lack of quantitative data on major international trends, stocks and flows. The shortcomings of existing data operate on many levels and result from a multitude of factors.

Issues such as ambiguous definitions about who constitutes a migrant, and varying classification systems across time and space represent important hindrances in producing internationally comparable statistics. Even though a focus on stocks as opposed to flows might prove more workable, the use of differentiated techniques of data measurement, collection and collation offer quite a challenge to any migration researcher. This issue will remain prominent until standardised international practices are established. The varying quality and comparability of different data sources have to be taken into account when undertaking data-based research. Reliability of data is not the only problem to work on though, as in many cases the very availability of data is an issue. The absence of data for whole regions or time periods, as well as the use of tentative estimates with regard to ‘irregular migration’ means important gaps remain to be filled.

Despite all the limits outlined above, data is needed, and there is little alternative to documenting and processing the raw data available from individual countries, whilst pragmatically acknowledging the unavoidable shortcomings. (See 'Quantifying the Bilateral Movements of Migrants’, Sep 05 (WP-T13). Within this framework of understanding, the Migration DRC seeks to contribute to the process of data compilation and thus support further evidence-based research in the area of migration.

To that end, the Migration DRC has been working on a set of innovative database projects, including a unique catalogue of existing household survey and census datasets that contain information about migration in developing countries (Migration in National Surveys or MiNS) and a global data base of origin-destination migrant stocks by country and economy.