This paper provides an explanation for the continued existence of gender discrimination in competitive labour markets and analyzes the effects of policies designed to alleviate it. Unlike previous explanations of gender discrimination, this theory arises from the interaction between women and men within the household, and does not rely on inherent asymmetries between women and men. Even though discrimination is seen to be related to factors which can be thought external to the labour market, such as higher job turnover and labour market exit rates for women, policies which target only labour market outcomes, and do not deal with external factors, can both lead to reduced discrimination and also alter external factors, thereby reducing discrimination further. However, policies aimed at external factors will, in general, be less effective in reducing discrimination unless combined with more direct policies. (C) 1998 Elsevier Science S.A.