ABSTRACT
Students of social mobility in modern societies customarily make a great deal of the distinction between mobility connected with trends in technology and the division of labor, and mobility independent of such secular trends. Relatively little attention has been paid to the profile of the division of labor at the starting point in research on social mobility. Just as the division of labor at the starting point was not identical in the various societies studied by investigators of social mobility, so were changes in the division of labor from one generation to the next quite diverse, both in degree and in kind. The index of net occupational change or mobility was defined earlier as the proportion of sons who would have to shift occupation if the distribution of sons were to match that of fathers. One other point concerning the indices of net occupational mobility affects their significance for the changing occupational structure of the society as a whole.
