Party System Saturation Forces Adaptation, Not Exit, in 21 Democracies

Insights from the Field

Party System Saturation

Time Series Analysis

Western Democracies

Electoral Alliances

Adapt or Perish: How Parties Respond to Party System Saturation in 21 Western Democracies, 1945-2011 was authored by Marc van de Wardt and Arjen van Witteloostuijn. It was published by Cambridge in BJPS in 2021.

Contrary to previous findings that suggest parties exit during system oversaturation (PSS), this study reveals they instead form alliances. Analyzing data from 522 parties across 357 elections between 1945 and 2011 in Western democracies, we find PSS leads parties toward entering electoral alliances more often than exiting or merging.

How do parties adapt?️⃣

• By increasing the nicheness of their policy platform

• Through forming new alliances

• Occasional merging among older parties

These strategies highlight limited adaptation capacity despite PSS. Why does this matter? This discovery offers fresh insights into political party dynamics and challenges electoral models.