Does Party-System Fragmentation Affect the Quality of Democracy?

33 Pages Posted: 12 Mar 2020 Last revised: 1 Apr 2020

See all articles by Vicente Valentim

Vicente Valentim

European University Institute

Elias Dinas

University of Oxford

Date Written: February 13, 2020


Does party-system fragmentation affect the quality of democracy? Providing causal evidence to answer this question is difficult because the characteristics of the party system are endogenous to many other dynamics in a polity. We overcome this issue by putting forward an instrument for the number of parties in a system, based on the level of fragmentation added by parties that narrowly make it to parliament. We then test the effect of party-system fragmentation on the quality of democracy, drawing upon a large battery of outcomes. Running against previous literature, we find that a higher number of parties leads to more fractionalized governments but it has no impact on democratic outcomes. The null effect persists after using a large number of different model specifications, operationalizations of the treatment variable and subsamples. Our results cast doubt on the normative implications of party-system fragmentation.

Keywords: party systems, quality of democracy, null findings, instrumental variables, causal inference

Suggested Citation

Valentim, Vicente and Dinas, Elias, Does Party-System Fragmentation Affect the Quality of Democracy? (February 13, 2020). Available at SSRN: or

Vicente Valentim (Contact Author)

European University Institute ( email )

San Domenico di Fiesole

Elias Dinas

University of Oxford ( email )

Mansfield Road
Oxford, Oxfordshire OX1 4AU
United Kingdom

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