Opportunism describes the short-term maximization of human satisfaction without regard to the impact of such behavior on others and without regard to the accepted norms of behavior in the community.

Such forms of behavior have disintegrating, hence harmful long-term consequences; they make human actions less predictable over the long term. Thus, it is opportunistic to satisfy one’s appetite by stealing from others, or to forget repaying one’s contractual debts.

“By opportunism I mean self-interested seeking with guile.

This includes, but is scarcely limited to, more blatant forms, such as lying, stealing, and cheating” (Williamson, 1985, p. 47).

It is the role of institutions, which must include sanctions for violations, to suppress opportunism.

When people feel they can get away with opportunistic behavior, because those whom they short-change do not know and will not find out, they fall prey to ‘moral hazard’.