Social mobility: what is it and why does it matter?

Abstract

The definition of social mobility is the object of some discussion, and although there is a common thread that runs through all of these discussions, the actual definition varies from study to study. There is agreement that social mobility refers to “movements by specific entities between periods in socioeconomic status indicators” (Behrman, 2000) and that it aims to quantify “the movement of given [entities] through the distribution of economic well-being over time, establishing how dependent one’s current economic position is on one’s past position, and relating people’s mobility experiences” to the overall conditions of the economy in which they operate (Fields, 2000). Differences arise, however, when an attempt is made to endow these definitions with empirical content (i.e., when an effort is made to determine what variable should be used to measure mobility, what exactly should be considered “movement” in a distribution, or what time spans should be used to evaluate mobility). In the following discussion, we briefly comment on some of the conceptual issues that have been raised in the literature on mobility. Among the multiple considerations concerning the definition of mobility, in this paper we define social mobility as a situation in which the relative economic status of an agent is not dependent on starting conditions such as parental income or family background. Therefore, analyzing the determinants of mobility involves exploring the channels through which offspring’s income is correlated to its parents’, such as inherited bequest, education, formal rules, skills, opportunities, working spirit, among many others. As parental linkage is a source of differences in income among individuals, there is a deep relation between social mobility and inequality. They are jointly determined, and the most prevalent theoretical association between mobility and inequality is negative; since structural conditions that lead to low mobility also tend to favor unequal outcomes.