Purpose – The purpose of this paper is to examine the underlying exchange mechanisms between ethical leadership behavior and affective commitment. The authors hypothesized that ethical leadership behavior enhances perceived organizational support (POS), which then raises employee affective commitment. The authors further predicted that economic exchange weakens such indirect effect of ethical leadership on affective commitment via POS. Design/methodology/approach – Using a two-phase survey, the authors tested the hypotheses with a sample of 176 bank employees in Macau using hierarchical regression analysis and bootstrapping. Findings – POS was found to mediate the relationship between ethical leadership behavior and affective commitment, whereas economic exchange was found to moderate the ethical leadership behavior – POS relationship as well as its indirect effect on affective commitment via POS. Originality/value – By identifying POS as the mediator and economic exchange as the moderator, this study enhances our knowledge of the dynamics of multiple exchange mechanisms linking ethical leadership behavior to affective commitment.