Prior studies have provided explanations for the presence, use and dissemination of codes of corporate ethics or codes of corporate conduct of business corporations. Most such explanations are functional in nature, and are descriptive as they are derived from the codes and their associated documents. We search for more underlying explanations using two complementary theories: first, social contract theories explaining the exogenous and endogenous reasons of organizational behavior, and then institutional theory explaining why organizations take similar measures in response to (...) institutional pressures. Based on our explanations, we contend that the codes and their use and dissemination are arising from underlying social and institutional pressures for firms to continuously validate their existence in the face of increasing changes and recurrent uncertainties. (shrink)