Laissez-faire leadership has received much less attention than have the 3 transactional leadership dimensions of the Multifactor Leadership Questionnaire (MLQ). However, laissez-faire leadership has shown strong negative relationships with various leadership criteria, and the absence of leadership (laissez-faire leadership) may be just as important as is the presence of other types of leadership. This article focuses on a single type of laissez-faire leadership (i.e., the lack of response to subordinate performance). Using a reinforcement perspective, the authors developed measures and examined the effects of the lack of performance-contingent reinforcement in 2 forms: reward omission (leader nonreinforcement of good subordinate performance) and punishment omission (leader nonreinforcement of poor subordinate performance). They found strong evidence in support of the construct validity of the new measures and found that omission was related to follower satisfaction with the leader, subordinate-rated leader effectiveness, subordinate-perceived role clarity, and supervisor-rated subordinate performance. (PsycINFO Database Record (c) 2008 APA, all rights reserved).