Concept and four dimensions
Huntington (1968) defined institutionalization as the process by which organizations and procedures acquire value and stability. Mainwaring and Scully (1995) applied this to party systems with four dimensions: stability in patterns of interparty competition, party roots in society, the legitimacy of parties and elections, and party organizations independent of individual leaders. The higher these are, the easier it is for voters to hold governments accountable through parties.
Measurement: electoral volatility
Pedersen (1979) proposed a volatility index, the sum of absolute changes in party vote shares between elections divided by two, which is widely used as an indicator of institutionalization. Mainwaring and Torcal (2006) showed that third-wave democracies have much higher volatility than Western Europe, with parties easily appearing and disappearing and personalistic politics strong. Mainwaring and Zoco (2007) found that volatility depends more on when democratization took place than on how long democracy has lasted.
Party level and system level
Randall and Svåsand (2002) distinguished the institutionalization of individual parties from that of party systems, proposing elements such as systemness, value infusion, autonomy and reification. Panebianco (1988) described party organizational institutionalization in terms of autonomy from the environment and internal systemness. Weak institutionalization is discussed as raising the risk of populist outsiders and democratic backsliding.
FAQ
- What is party system institutionalization in simple terms?
- A stable situation in which parties do not change dramatically from election to election and are rooted in society, so people trust and vote for parties.
- How is it measured?
- A common measure is the Pedersen volatility index, which shows how much party vote shares shift between elections.
Sources reviewed: 2026-10-26
References
- Huntington, S. P. (1968). Political order in changing societies. Yale University Press. Political institutionalization.
- Pedersen, M. N. (1979). The dynamics of European party systems: Changing patterns of electoral volatility. European Journal of Political Research, 7(1), 1–26. The volatility index.
- Mainwaring, S., & Scully, T. R. (Eds.). (1995). Building democratic institutions: Party systems in Latin America. Stanford University Press. Four dimensions of institutionalization.
- Randall, V., & Svåsand, L. (2002). Party institutionalization in new democracies. Party Politics, 8(1), 5–29. Party versus system level.
- Mainwaring, S., & Torcal, M. (2006). Party system institutionalization and party system theory after the third wave of democratization. In R. S. Katz & W. Crotty (Eds.), Handbook of party politics (pp. 204–227). Sage. Third-wave comparisons.
- Mainwaring, S., & Zoco, E. (2007). Political sequences and the stabilization of interparty competition: Electoral volatility in old and new democracies. Party Politics, 13(2), 155–178. Timing of democratization.
- Panebianco, A. (1988). Political parties: Organization and power. Cambridge University Press. Organizational institutionalization.