Common Method Bias in PLS-SEM: A Full Collinearity Assessment Approach

What Is Common Method Bias?

Common method bias, in the context of PLS-SEM, is a phenomenon that is caused by the measurement method used in an SEM study, and not by the network of causes and effects in the model being studied. For example, the instructions at the top of a questionnaire may influence the answers provided by different respondents in the same general direction, causing the indicators to share a certain amount of common variation. Another possible cause of common method bias is the implicit social desirability associated with answering questions in a questionnaire in a particularly way, again causing the indicators to share a certain amount of common variation.

A mathematical understanding of common method bias can clarify some aspects of its nature. The adoption of an illustrative model can help reduce the level of abstraction of a mathematical exposition. Therefore, our discussion is based on the illustrative model depicted in Figure 1, which is inspired by an actual empirical study in the field of e-collaboration (Kock, 2005; 2008; Kock & Lynn, 2012). The illustrative model incorporates three latent variables, each measured through six indicators. It assumes that the unit of analysis is the firm.