What accounts for the large and ever-changing number of political parties that contest Indian state elections? In this paper we test an equilibrium model of political parties where the number of parties depend on the average size of state constituencies, the heterogeneity of the state’s electorate, state per capita income as well as constitutional and legislative rules that directly affect party numbers. Extending the analysis to consider the effects on entry and exits highlights those factors that have affected party turnover instead of or in addition to changing aggregate party numbers. Comparison of the effects on numbers with those on the effective number of parties (ENP) suggests that the model explains variations in the number of smaller sized parties that are a more transitory part of the electoral process. Whether this implies that the model is more applicable to the lesser developed Indian states is examined by re-testing the model against a subdivision of states that differ by their stage of development. While most variables work in the same way, increases in the proportion of reserved seats have decreased both party numbers and ENP in lower income states, with the opposite occurring in higher income states. The effect of state partition has been to decrease party vote fragmentation more than party numbers.