A number of recent leadership studies have questioned whether situational variables are important moderators of leadership effectiveness. Pessimistic conclusions from these studies regarding situational modifiers challenge the foundations of path–goal and substitutes for leadership theories. However, analysis of this research reveals questionable methodological practices that cast doubt on the validity of these conclusions. This article discusses two methodological issues, elucidates specific flaws in methods used in recent leadership studies, and makes recommendations for the use of moderated multiple regression (MMR) in leadership studies. We argue that low power to detect moderators and inappropriate use of regression methods can account for the lack of confirmatory findings regarding moderators. Comparative analysis using a previously published data set provides strong support for major arguments presented in this article. We conclude that situational variables are important moderators of leadership effectiveness and are detectable using appropriate procedures.
Practitioners and leadership researchers have long assumed that the effectiveness of leaders is dependent upon situational factors. These situational variables are referred to as moderators if they interact with a leader behavior to change the leader's impact. Recent debate has focused on the prevalence of moderator variables and their interpretation. Conclusions from recent studies challenge the notion that situational variables are important moderators of the effect of leader behaviors on criteria Podsakoff & MacKenzie, 1997, Podsakoff et al., 1995, Podsakoff et al., 1993 and Podsakoff et al., 1993. If these conclusions are correct, the validity of two major streams of leadership research—path–goal House, 1971, House, 1996, House & Dessler, 1974 and House & Mitchell, 1974 and substitutes for leadership theories Howell et al., 1986 and Kerr & Jermier, 1978—must be questioned.
Researchers in other areas of organizational behavior, human resources management, industrial/organizational psychology, and related disciplines have also noted difficulties in detecting the existence of hypothesized moderating effects (e.g., Aguinis, 1995, Aguinis & Stone-Romero, 1997, Dunlap & Kemery, 1988 and McClelland & Judd, 1993). A number of factors have been identified across various literatures that affect the ability to detect moderators using moderated multiple regression (MMR). This article discusses these methodological issues, elucidates specific flaws in methods used in recent leadership studies, and makes recommendations for the use of MMR in leadership studies. We also provide data from previously published leadership studies to demonstrate our main points.
