Common method variance and specification errors: a practical approach to detection

The purpose of this study was to demonstrate how examining the bivariate correlations between items in self-report measures can assist in differentiating between possible common method variance vs. model specification errors. Specifically, social desirability was viewed as either a possible source of common method variance or as a theoretically meaningful construct that should be included in the model of interest (i.e., a specification error). In the first instance, LISREL was used, and the level of correlation between measures of social desirability and measures of the five constructs of interest was manipulated. These results provided some insight as to when one needs to be concerned about the possible "common variance effects" on the structural model. In the second instance, the correlations between measures of social desirability and the measures of only two constructs of interest were again manipulated. These analyses illustrated the point at which the omission of social desirability as a theoretically relevant variable began to result in a poor fit of the structural model.