by DAN CALLOWAY
Published 4 August 2010
WEAVERVILLE, NC - In this article, I will consider another example of a suppressor effect different from the example I provided in my previous article earlier this week. I have chosen an example of suppressor effect, which is taken from a study conducted by Teas (1983), and which was research employing structural equation analysis used to replicate and extend previous salesforce role stress research conducted by Churchill, G., Ford, and Walker, O. (1976) by testing various hypotheses regarding the relationships among the criterion variables – sales supervisory behavior, salesforce role stress, and salesforce job satisfaction. Based on previous research, there were four supervisory behavior variables (or predictor variables) that were hypothesized to be related to salesforce role stress – initiation of structure, leader consideration, participation, and feedback. The results of the Teas research indicated that salesforce supervisory behavior was positively related to salesforce perception to role stress. Moreover, the research points to the fact that role conflict, organizational communication, leadership consideration, and leader initiation are significant predictors of salesforce job satisfaction (criterion variable). The model suggested by the hypothesis in Teas’s research was a causal model in which job experience, leader consideration, leader initiation of structure, salesforce participation, and performance feedback were predictors of the sales person’s job satisfaction. Structural equations relating the model were developed by Teas and zero order correlations and alpha coefficients were constructed. The findings of the study revealed that the leader’s initiation of structure is positively related (p < 0.05 for a two-tail test) the salesperson’s perceived role conflict. This finding supports Walker, Churchill, and Ford, 1975) and does not support the House and Rizzo (1972) hypothesized negative initiation of structure/ role conflict linkage.
What is noteworthy in the Teas (1983) research is that the pairwise correlation between initiation of structure and role conflict is only 0.048. The significant partial regression coefficient thus suggested the presence of suppressor effects (Churchill, Ford, & Walker, 1976, p. 87-91) in which one or more variables in the role conflict equation is suppressing some of the variance in initiation of structure that is not related to role conflict. As suggested by Churchill, Ford, and Walker, hierarchical multiple regression was used to identify the suppressor variables. The procedure consisted of estimating a simple role conflict equation using as the single explanatory variable. Next, a series of multiple regression equations with each equation containing two explanatory variables – initiation of structure and one of the other explanatory variables from the model. Evidence of the suppressor effects appeared when the partial regression coefficient on initiation of structure increased upon addition of a variable to the equation (Churchill, Ford, & Walker, 1976, p. 102). The results of this exercise procedure revealed two variables – consideration and participation were behaving as suppressors variables. Thus, the standard partial regression figure of 0.048 increased to 0.156 when consideration was added to the equation and from 0.048 to 0.142 when participation is added. The findings thus suggest as predicted by Churchill, Ford, and Walker that close supervision may decrease the sales person’s flexibility in meeting diverse role expectations and, thus, may increase the likelihood of role conflict. In addition, the evidence of these suppressor variables suggests an explanation for the significance of the closeness of supervision variable in the Walker, et al. (1975) study may be that the suppressor variables identified were not included in their role conflict model.
References:
Churchill, Gilbert A., J., Ford, N. M., & Walker, Orville C., J. (1976). Organizational climate and job satisfaction in the salesforce. Journal of Marketing Research, 13, 323-332.
House, R. J., & Rizzo, J. R. (1972). Role conflict and ambiguity as critical variables in a model of organizational behavior. Organizational Behavior and Human Performance, 7, 467-505.
Teas, R. (1983). Supervisory behavior, role stress, and the job satisfaction of industrial salespeople. Journal of Marketing Research, 20, 84-91.
Walker, O., Churchill, G., & Ford, N. (1975). Organizational determinants of the industrial salesman’s role conflict and ambiguity. Journal of Marketing, 39.
