This article argues that the impact of veto points on a government's policy outcomes depends crucially on the degree of institutionalization of the party system. Specifically, the article claims that two dimensions of party system institutionalization – stability of relations between parties and between parties and voters – condition the ability of the opposition to block governments' policy plans through veto points. It showcases this argument by applying the method of causal process tracing to a comparative analysis of health policy reforms in Slovakia (2002–2004) and Hungary (2006–2008).

Over the last decades, Western European party systems have experienced growing levels of electoral volatility and the recurring emergence of successful new parties. This evidence calls into question the issue of party system institutionalization (PSI), a topic taken for granted so far in Western Europe, following the conventional wisdom that party systems are highly institutionalized in this region. This article tackles this issue and provides some contributions: it offers a theoretical clarification of PSI and develops an index allowing for cross-country and cross-time comparability; it looks for an explanation, by testing the impact of various potential determinants and their changes over time. Covering 324 elections in 19 countries since 1945, the analysis shows that, since the 1970s, a process of de-institutionalization is going on and that PSI is mainly a function of the cleavage structure and the number of parties, with economic performance becoming relevant only in the last period.

This essay reviews five important recent books on party system institutionalization, party collapse and party building. The first section analyses broader lessons about party system institutionalization derived from these books. What have we learned about how party system institutionalization varies over time and space and about its causes? All five volumes underscore the difficulty of institutionalizing democratic party systems in contemporary Asia, Africa and Latin America. At the same time, they demonstrate that there have been some successful cases of party building and party system institutionalization. In all three regions, variance across countries is great. The three books on Latin America show that sharp conflict and programmatic differences are good for institutionalization, partially countering earlier arguments about the perils of polarization. Across regions, erstwhile authoritarian ruling parties have sometimes helped to forge institutionalized party systems under competitive regimes. The rest of the essay analyses the three single-authored books in some detail and provides brief overviews of the two edited volumes.

Formally institutionalized party organization is usually considered a prerequisite for the development of programmatic linkages between parties and voters. However, in this article I show that political parties in South Korea have succeeded in stabilizing interparty competition through programmatic linkages without making any significant efforts to build a formal organizational base. In fact, it could be argued that South Korea is a “partyless” democracy, as political parties get easily captured by the interests of ambitious politicians, thus failing to establish themselves as independent actors. I therefore make a more general argument about the concept of party system institutionalization: we need to rethink the current practice of aggregating the different attributes of party system institutionalization into a single scale, as these attributes do not seem to be connected in a linear fashion.