Migration data using social media : a European perspective

Migration is a top political priority for the European Union (EU). Data on international migrant stocks and flows are essential for effective migration management. In this report, we estimated the number of expatriates in 17 EU countries based on the number of Facebook Network users who are classified by Facebook as "expats". To this end, we proposed a method for correcting the over- or under-representativeness of Facebook Network users compared to countries' actual population. This method uses Facebook penetration rates by age group and gender in the country of previous residence and country of destination of a Facebook expat. The purpose of Facebook Network expat estimations is not to reproduce migration statistics, but rather to generate separate estimates of expatriates, since migration statistics and Facebook Network expats estimates do not measure the same quantities of interest. Estimates of social media application users who are classified as expats can be a timely, low-cost, and almost globally available source of information for estimating stocks of international migrants. Our methodology allowed for the timely capture of the increase of Venezuelan migrants in Spain. However, there are important methodological and data integrity issues with using social media data sources for studying migration-related phenomena. For example, our methodology led us to significantly overestimate the number of expats from Philippines in Spain and in Italy and there is no evidence that this overestimation may be valid. While research on the use of big data sources for migration is in its infancy, and the diffusion of internet technologies in less developed countries is still limited, the use of big data sources can unveil useful insights on quantitative and qualitative characteristics of migration.