Research on ethical norms has grown in recent years, but imprecise language has made it unclear when these norms prescribe “what ought to be” and when they merely describe behaviors or perceptions (“what is”). Studies of ethical norms, moreover, tend not to investigate whether participants were influenced by the prescriptive aspect of the norm; the studies primarily demonstrate, rather, that people will mimic the behaviors or perceptions of others, which provides evidence for the already well-substantiated social proof theory. In this (...) review article, we delineate three streams of norms research in business ethics: behavioral, perceptual, and prescriptive. We argue that by properly categorizing norms, and designing studies to investigate when prescriptions, more than mere mimicry, improve ethical outcomes in organizations, researchers can enhance managers’ efforts to promote ethical outcomes in organizations. (shrink)