Supportive leadership and job performance: Contributions of supportive climate, team-member exchange (TMX), and group-mean TMX

Although much research has investigated the effects of supportive leadership on supervisor–subordinate relationships, the mechanism through which supportive leadership affects horizontal relationships among subordinates remains underexplored. Using psychological climate theory, we develop a conditional process model by which supportive leadership influences team-member exchange (TMX) via supportive climate and the relationship between TMX and the individual employee's job performance is moderated by group-mean TMX. To test our proposed model, we conduct a total of three studies. Study 1 is a scale validation study for our supportive climate measure. Study 2 examines the effect of supportive leadership on TMX through supportive climate and the moderating role of group-mean TMX for the TMX–job performance relationship. Study 3, using a repeated measure design, investigates the causal ordering among the study variables. Our results provide compelling evidence for the conceptual model. We discuss the theoretical implications of our findings.