The Yasuda Index of Social Mobility: A Proposal for Its Modification

The Yasuda index Y is based on a representation of “pure” mobility that contradicts fundamental assumptions underlying the definition of mobility components. Using a matrix representation of pure mobility the index is modified so that it retains its theoretical appeal and validity. Under the proposed modification the index is a ratio of the two amounts of pure mobility - that which is extracted from the matrix of observed mobility and that which is extracted from the corresponding matrix of “perfect mobility.” For a given matrix of observed transitions both quantities are determinable by means of linear programming.