INTRODUCTION

In the previous two chapters, I developed and tested a theory of aggregation incentives. In the next three chapters, I use the theory to help explain the nature of party system development in Thailand and the Philippines. As discussed in the introduction, Thailand and the Philippines provide interesting variations on both the dependent and independent variables, which allow me to further investigate the causal mechanisms lying between the explanatory variables of interest (the size of the aggregation payoff and probability of capturing that prize) and the outcome of interest – the degree of aggregation. Even though elections in each country have often produced a comparatively large number of parties at the national level, aggregation has generally been much better in the Philippines vis-à-vis Thailand. In the following three chapters, I first describe the nature of intra-district and cross-district coordination in Thailand and the Philippines, utilizing unique datasets of district-level electoral returns in each country. Then, using the theory described in Chapter 2, I explain why the party system in each country looks as it does. In so doing, I answer the question of why, given similar majoritarian electoral institutions, there has until recently been more parties in Thailand than in the Philippines. Finally, I utilize episodes of institutional reform in each country to conduct comparative statics tests of the theory.