Unusual electoral systems and political hegemony. Evidence from the argentine subnational districts

A few years after the democracy was restored in 1983, Argentina has witnessed one of the most intense periods of political reforms with the proclaimed objective of modernizing the electoral system and extended political rights to province’s constituencies. Reforms included various critical items such as modifications in the electoral system which ended up changing the political game. This paper provides empirical evidence on the role played by the Double Simultaneous Voting System (DSVS), that performs simultaneously primaries and general elections, and its variations, grouped under the heading of Apparentment lists (ALs), that includes the so –called “Colectoras”, “Acoples” and “Adhesiones”, on the political competition of subnational districts for the period 1987 – 2015. DSVS was in force in 14.5% of the gubernatorial, 20.6% of the legislative and 23.8% of the mayoral elections. Likewise, the ALs were used in 33.9% of local legislative elections. Results from a panel data of eight gubernatorial elections and all 24 subnational jurisdictions show that DSVS and ALs diminish the effective number of parties, increase the margin of victory of the incumbent party and diminish the probability of party alternation and improve the probability of reelection of the incumbent governor.