Without accurate migration figures we cannot gain a reliable overview of the size and movement of the population – crucial inputs to government for decisions on infrastructure, amenities and sound economic forecasting. In the UK and the rest of Europe, inconsistent data from a range of disparate sources have previously made it difficult to quantify migration and make accurate population forecasts.
A three-year research collaboration between the ESRC Centre for Population Change and the Southampton Statistical Sciences Research Institute culminated in 2009 with a pioneering methodology for obtaining reliable and consistent estimates of international migration between European countries. The team, led by James Raymer, Jakub Bijak and Peter W.F. Smith, estimated the full migration flow tables for Europe (representing the gross flows of immigration and emigration and the associations between countries) with the associated measures of error.
The researchers advised the UK's Office of National Statistics (ONS) on how to improve their methodology and suggested methodological improvements, such as pooling data from different sources and separating various migration streams when setting the assumptions for population projection. This work has become an integral part of ONS operations, in turn improving the daily working methods of public bodies relying on population statistics – ultimately affecting the users of public services all across the UK.