This paper presents the available sources in Spain to analyze the evolution of migration, focusing on quantifying the contingent of migrants and migration flows. Both internal and international migration are considered, since many sources are available to study them. The article distinguishes purely statistical sources from those based on administrative records, as well as those that study the whole universe from the ones based on surveys, stressing the need to rigorously distinguish contingents from flows.
Statistical sources; Internal migration; International migration; Migrants; Foreigners