This study addresses the question of why ideological parties and party systems emerge in some democracies but not in others, with a special focus on developing democracies. In delving into this question, I highlight the functions of ideology as a multilevel phenomenon, and examined the party-voter linkage mechanism based on policy programs at various angles. I assume that a party has strong ideological linkage (a) when those in the electorate who support the party feel a close ideological affinity for the party, (b) when the party has a clearly defined and ideologically distinct program, and (c) when party activists are ideologically motivated and coherent within the party. Focusing on each dimension, each empirical chapter evaluates the effects of institutions, socio-economic conditions, and democratic conditions. The methodology used for this multilevel approach is 'tripartite,' combining statistical analysis (large-N cross-national comparison), content analysis (case study) and traditional surveys (inter- and intracountry comparisons). First, by examining ideological affinity between parties and voters in 46 democracies, I find that the extent of perceived ideological affinity is determined by the age, size, and ideological position of a party and that institutional and economic factors are more important than democratic conditions for the development of ideological congruence of a party system. Second, by analyzing South Korean party platforms, I find that parties in this developing democracy have evolved to programmatic ones over time since democratic transition. Lastly, by investigating the motivation and ideology of party activists in Mongolia and South Korea, I find little evidence that activists who are wealthy or are living in a wealthy district or a country are more policyseeking than those who are not, while activists in a wealthy district or country are more ideologically coherent as a group within the party. This study contributes towards a better understanding of party-voter linkage mechanisms: it proposed a conceptually-decomposed approach to linkage, provides novel measures for comparisons across parties, across countries and over time, offers a close examinations of Asian cases that were underexplored, and lastly illuminates the role of activists as a linkage themselves with the addition of a new survey dataset.
