Labor Studies Journal, Ahead of Print.
This study draws on three well-established streams of leadership research: transformational leadership, servant leadership, and five-factor personality theory and applies them to the labor union context. The study tested the relationship between these theories and both leader and union effectiveness. The sample consisted of 240 respondents who rated the leadership of 60 participants in the 2018 and 2019 Harvard Trade Union Program. Results indicated that the best predictors of both leader effectiveness and union effectiveness were the transformational and servant leadership styles. In contrast with other research, the five-factor personality variables (extraversion, conscientiousness, emotional stability, openness, and agreeableness) had no significant relationship with leadership effectiveness after controlling for the leadership style models. Only two of the five personality variables, extraversion and emotional stability, were related to union effectiveness after controlling for the effects of transformational and servant leadership. Discussion includes implication for labor educators.