Why Brazil’s Parties Concentrate in Governors but Fragment in the Lower House

📊 What the new data cover

This article presents a newly assembled dataset documenting electoral alliances (coligações) formed to contest Brazilian general elections from 1986 to 2014. The collection records alliances across both gubernatorial and national lower-house contests, allowing direct comparison of coordination across offices.

🔗 How alliances across offices are linked

Evidence shows that alliances created for gubernatorial and lower-house elections are not independent: many are joint strategies that span concomitant contests. Those joint alliances operate as complex coordination mechanisms used to manage the entry and withdrawal of candidates across offices that are governed by different electoral rules.

📌 Key findings

• Joint alliance strategies produce interlinked dynamics across levels: party concentration in subnational executive (gubernatorial) contests and party fragmentation in the national lower house.
• These contrasting patterns are driven by the emergence of political parties that specialize in contesting particular offices, prompting parties to enter or withdraw strategically across simultaneous elections.

💡 Why it matters

The results reveal that multi-office coordination—shaped by differing rules for concurrent contests—helps explain major features of the Brazilian party system: concentrated competition for governors and fragmented competition in the lower house. Understanding these coordination strategies is essential for interpreting party behavior and institutional effects in multi-level electoral settings.