Searching for outcomes of leadership: A 25-year review

A significant question in management research is, "What criteria should be used to evaluate the effects of leadership?" In this review, the authors systematically summarize various ways the field of leadership has (and has not) sought to answer questions about whether, when, and how leadership affects outcomes. A total of 1,161 empirical studies over 25 years, spanning micro- and macro-oriented perspectives, were content coded to answer six basic questions that set the scope of leadership science. The authors first descriptively summarize these criterion issues in the empirical literature and draw comparisons across areas (e.g., To what extent have leader-member exchange, transformational, and strategic leadership research differentially examined various outcomes?). Second, the authors explore the implications of criterion selection issues for the further advancement of leadership theory and offer concrete recommendations for future leadership research.