Replication Data for: Informal Coalitions in Action: Party Legislative Performance in Brazilian Presidentialism

The legislative success of presidential agendas in Brazil has traditionally been attributed to formal coalitions formed by the Executive. While the centrality of these coalitions is widely recognized, a key question remains: do formal governing coalitions secure sufficient votes to guarantee this success? To explore this question, the study develops a Legislative Performance Index (LPI) that measures the contribution of each party’s votes to the approval of Executive-backed bills. Drawing on data from 2,030 roll-call votes in the Chamber of Deputies spanning 1995 to 2016, the analysis reveals that presidents have consistently achieved high legislative success rates – with a 92% approval rate of their legislative agenda. However, votes from formal coalitions alone would have yielded substantially lower approval rates, at just 66%. In practice, majority governance in Brazilian presidentialism has relied heavily on support from parties outside formal coalitions, with informal coalitions playing a crucial role at various times. These findings underscore the importance of analyzing party behavior beyond formal alliances and recognizing the interplay of formal and informal coalitions in shaping legislative outcomes.