The Encuesta de Migraciones (Migration Survey) taken from the Encuesta de Población Activa (Spanish Labour Force Survey) has shown a low and decreasing intensity of migration flows in Spain over the past ten years, even when the Spanish economy was growing and creating employment. This surpnse scenario is even more so when we compare these data with other related satistical information. Our analysis of the methodology used by the Instituto Nacional de Estadística (Spanish National Statistical Institute) has enabled us to establish the existence of an important and significative problem whereby mobility is underestimated by the said satistics.

Keywords: migration, Spanish Labour Force Survey and methodology.