The use of two-stage least squares (2SLS) for the estimation of feedback linkages is inappropriate for nonorthogonal data sets because 2SLS is extremely sensitive to multicollinearity. It is argued that what is needed is use of a different estimating criterion than the least squares criterion. Theoretically the variance normalization criterion has…

The study of the same people at several occasions is known by various names: panel studies, multi-wave, multi-variable models, cohort analysis, and gain score analysis. The use of econometric concepts, path analysis, and structural equation analysis to study multi-wave, multi-variable models became widespread in methodological practice in the late…