Communism remained an important focus especially during the 1950s and 1960s. Colonialism and racism were important issues that arose. In general, there was a marked trend towards a pragmatic approach to political issues, rather than a philosophical one. Much academic debate regarded one or both of two pragmatic topics: how (or whether) to apply utilitarianism to problems of political policy, or how (or whether) to apply economic models (such as rational choice theory) to political issues. The rise of feminism, LGBT social movements and the end of colonial rule and of the political exclusion of such minorities as African Americans and sexual minorities in the developed world has led to feminist, postcolonial, and multicultural thought becoming significant. This led to a challenge to the social contract by philosophers Charles W. Mills in his book The Racial Contract and Carole Patemen in her book The Sexual Contract that the social contract excluded persons of colour and women respectively.