The Identification Problem and Theory Building: The Case of Status Inconsistency

The identification problem arises when there are too many unknowns for solution. Identification can be achieved in one-way causal situations by making assumptions about the error terms, but these are often unrealistic. Even this procedure breaks down when exact mathematical relationships are assumed among some of the variables, as is the case where status inconsistency (or social mobility) is taken as a difference between two statuses. In such situations one must make additional restrictive assumptions; otherwise the separate effects of the component factors cannot be isolated. In the case of status inconsistency, identification may be achieved by: (1) making a priori assumptions regarding the signs or magnitudes of some of the coefficients; (2) finding and measuring additional exogenous variables that appear in some but not all of the equations; or (3) postulating certain kinds of nonlinear relationships.