How post-electoral intraparty rank affects party unity in the Brazilian Chamber of Deputies

Abstract: Within the fields of electoral studies and legislative politics, the interest of this study is the Brazilian electoral system and the unity of the parties it produces. Specifically, I ask how post-electoral intraparty rank affects party unity. I determine post-electoral intraparty rank by comparing deputies’ vote share of the total national vote count. By compiling a database of 48 roll-call votes of 37 Federal Deputies from São Paulo, I compare how often the deputies toe the party line to their vote share. I also test for the geographical concentration of votes in cases where I find it relevant. My hypothesis is that deputies elected with a low vote share will vote according to their party’s recommendation to a larger degree than those deputies with a strong electoral base. I find that, based only on roll-call vote analysis, the complete sample does not demonstrate a strong relationship between voting agreement and vote share (or post-electoral rank). However, by analyzing significant cases individually, I do find a basis for my hypothesis, as well as indicators of theoretical consistency in the sample. The basis is for the most part strengthened when controlling for vote concentration. I conclude that deputies whose largest electoral base is centered in cities seem to be more autonomous in their voting, most likely for ideological reasons rather than reasons motivated by pork-barrel spending.