Can legislative majorities shape budgets? A comparative analysis of presidential systems in Latin America

In separation of powers systems, in theory, legislative and executive branches must concur for policies to be enacted. However, empirical research, especially on Latin American cases, suggests that rather than reaching a compromise, it is common for the executive to make unilateral decisions, leaving the legislature marginalized in the policymaking process. Contrary to this trend, I argue that understanding important policy choices, including the national budget, requires considering the formal powers assigned to the president and the assembly, in interaction with their ideological divergence. Examining 12 presidential democracies for the past 20 years, I investigate the legislative majority's success in determining government expenditures under various policymaking institutions. I identify a number of institutional scenarios where legislative majorities are highly likely to succeed, while in other configurations, their success depends on their ideological divergence from the president.