Affirmative action policies, though adopted in many countries around the world, have been controversial. This paper will test some of the claims made by supporters and critics of the policy, such as whether the policy is needed to increase representation or whether education and mobilization would lead to the inclusion of the previously excluded groups, by comparing representation in the Parliament in three multi-ethnic South Asian countries: India and Nepal where affirmative action in the political sector was adopted around six decades and this decade respectively and Sri Lanka where the policy has not been adopted in the political sector. Nepal provides an opportunity to examine the effect of policy by comparing conditions of target groups before and after 2008. Findings based on comparison of target group’s performance before and after the policy was implemented can be more robust than evaluations based on post-policy performances only. If affirmative action policies increased inclusion in the polity after it was adopted compared to the previous years, we can be more certain about the contribution of the policy in promoting an inclusive and just society, and vice versa. Many ethnic and caste groups were represented in the Parliament for the first time in 2008 while many other previously under-represented groups increased their representation. India, on the other hand, provides a social quasi-experimentation setting because it targeted AA policy to some excluded groups (Scheduled Caste and Schedule Tribes) but not to others (Muslim) over a same period and largely across similar socio-economic policy context. More or less proportional representation of the SC and ST but continuous under-representation of Muslims points to the efficacy of the policy. It also shows that universal adult franchise and periodic elections as well as increased educational attainment are not enough to provide equitable representation. The Sri Lankan data allows comparison between states with AA policies and that without to retest/verify the consequences of not adopting the policy. The three cases demonstrate that the previously excluded groups’ do not gain proportionate representation with the passage of time and increase in education and mobilization; AA was necessary to increase representation.