Governments in the UK and many other countries have long sought to promote the diversity of their higher education institutions. However, diversity is hard to define, harder to measure and even more difficult to compare between countries. Most empirical analyses of the diversity of higher education systems use categorical variables, which shape the extent of diversity found. This study examines continuous variables of institutions' enrolment size and proportions of postgraduate, fulltime and international students to find the extent of variation amongst doctoral granting and all higher education institutions in the United Kingdom, United States and Australia. The study finds that there is less variety amongst all higher education institutions in the United Kingdom than in Australia, which in turn has much less variety than the United States. The paper argues that the extent of government involvement in higher education is not so important for institutional variety as the form that it takes. More tentatively, the paper suggests that the more limited the range of institutions for which government funding is available the stronger government involvement is needed to have variety among the limited range of institutions for which government financial support is available.