How Judges Think in the Brazilian Supreme Court: Estimating Ideal Points and Identifying Dimensions

We use NOMINATE (Nominal Three Step Estimation) (Poole and Rosenthal: 1983, 1997) to estimate ideal points for all Supreme Court Justices in Brazil from 2002 to 2012. Based on these estimated preferences we identify the nature of the two main dimensions along which disagreements tend to occur in this Court. These estimates correctly predict over 95% of the votes on constitutional review cases in each of the compositions of the Court which we analyze. The estimates are also used to (i) identify the median justice in each Court; (ii) analyze the strategic possibilities for the President to shift the median voter in the coming years; (iii) test different theories of judicial behavior; and (iv) analyze some specific seminal cases, including the landmark Mensalão trial, in which the court surprised experts and citizens by convicting high profile politicians members of the current ruling coalition. Although there is a large literature applying these methods to the US Supreme Court, their extension to non-US context is still underexplored. Similarly, although the study of the Supreme Court in Brazil has grown dramatically in recent years, most of this work is descriptive rather than analytical and the use of quantitative methods is rare. The main contribution of the paper is to identify that the main dimension along which preferences align in the Brazilian Supreme Court is for and against the economic interest of the Executive. This is significantly different than the conservative-liberal polarization of the US Supreme Court. Our estimates show that along this dimension the composition of the Court has been clearly favorable to the Executive's economic interests, providing the setting in which the dramatic transformation in institutions and policies that the country has undergone in last two decades could take place. Given that the Brazilian Supreme Court is highly independent and has the power to act as a crucial veto point, understanding its members' preferences and how they make their choices is key to understand the policy-making process and outcomes.