In the first case, movements are analysed by taking two points in an individual's life, while in the second movements between generations are examined (parents and children). The sociological tradition has stressed mobility in terms of social classes or occupational groups, whereas economists usually analyse mobility in terms of income (or education). To analyse mobility both between generations and over the life cycle of individuals, it would be desirable to have longitudinal information. Few panel data are available in the region, and they are usually from rotating panels of household surveys that are observed for a small number of rounds or collected unsystematically.40 Examples of this type of information are the rotating panel surveys of Argentina, Bolivarian Republic ofVenezuela, Brazil, Chile, Mexico, and Peru (Amarante, 2013).