3.2 Explanatory Variables
The explanatory variables used in this analysis were taken from the Spanish Labor Force
Survey (EPA). This is a rotating quarterly survey carried out by the Spanish National
Statistical Institute (Instituto Nacional de Estadística, INE). It is the most exhaustive and representative source of data for the Spanish workforce. Information about worker‘s personal characteristics such as gender, age, education level, occupation, economic sector,
family structure, the place of birth, nationality, type of contract and autonomous community from 2005 to 2009 can be found there. The given sample is composed of roughly 330.000 observations, from which about 260.000 observations provide full information about all variables.