73. Gerrymandering to survive: an explanation of the political conditions that shaped mayors’ decisions over an amalgamation process in Portugal

Rodrigues, M., Meza, O., & Navarro, C. (2025). Gerrymandering to survive: an explanation of the political conditions that shaped mayors’ decisions over an amalgamation process in Portugal. Local Government Studies, 51(5), 993–1015. https://doi.org/10.1080/03003930.2024.2404104This article examines how Portuguese mayors strategically used gerrymandering during the 2013 territorial reform to secure their political positions. The reform, imposed by the central government under the troika’s austerity measures, required the merger of sub-municipal units (SMUs) but allowed mayors discretion in determining specific boundaries. Acting as rational political agents, mayors manipulated the process to reduce political vulnerability, employing tactics such as packing (concentrating opposition SMUs) and diluting (merging opposition areas with supportive ones). A decision matrix identified four political scenarios, with the “Appealing” one—mayoral majority in the municipal assembly but minority among SMUs—showing the strongest incentive for gerrymandering. Empirical evidence from multinomial logistic regression confirmed that politically vulnerable mayors were up to nine times more likely to favor SMUs aligned with them. The study concludes that the amalgamation process was politically instrumentalized, illustrating how local reforms can serve electoral survival rather than broader public goals.