Quality & Quantity (2006) 40:129–143 © Springer 2006
Trend and Comparative Analysis of Inequality
of Social Opportunity
Centre National de la Recherche Scientiﬁque (CNRS), Groupe d’Etude des Methodes de
l’Analyse Sociologique (GEMAS), Paris, France.
Abstract. This article sets out a new method for the analysis of inequality of social oppor-
tunity. The shortcomings of the previous concepts and measures attempting to assess the
degree of openness of the mobility process independently of marginal effects are displayed.
The suggested new approach refers to relative opportunity distributions of individuals
according to their social origin. Starting from the premise that these distributions underly-
ing the observed allocation of social positions are continuous, it is assumed that it is possible
to compare them using straight lines. The various slopes of the lines represent inequality of
social opportunity coefﬁcients which permit trend and comparative analysis of the mobility
process net results.
Key words: inequality of opportunity, social mobility, exchange mobility, circulation mobil-
ity, odds ratios, gini index
Sociologists have long striven to distinguish two types of social mobility:
“structural” mobility and “exchange” or “circulation” mobility. The notion
of structural mobility refers to the changes in status forcibly brought about
by the differences in size of origin and destination categories. On the other
hand, the notion of exchange or circulation mobility refers to mobility
that arises from the intrinsic openness of the mobility process. Sociologists
have attempted to control for marginal effects (structural mobility) because
they sought to assess, in a comparative perspective, the importance of the
redistribution of social privileges attributed to the social processes at work.
While this framework has largely been abandoned, the aim of appraising
the intrinsic degree of openness of societies is still alive and needs concep-
The following sets out to review brieﬂy the major models developed thus
far, as well as the problems they raise. A new approach is then proposed,
based on the characterization of relative opportunity distributions of indi-
viduals according to their social origin. Starting from the premise that