Anatomy of an informal institution: The ‘Gentlemen’s Pact’ and judicial selection in Mexico, 1917–1994

The Mexican Constitution of 1917 granted the Supreme Court the power to handpick lower court judges and oversee their careers. For almost eight decades this capacity was not regulated. To fill this void, the justices began to take turns filling vacancies which developed into an informal institution – the so-called ‘Gentlemen’s Pact’. Using original archival data, we document and describe the birth and development of this practice and argue that it consolidated into an informal institution as the judiciary increased in size. We uncover the workings of this social norm that established a patronage model of judicial selection. Our analysis period ends in 1994, when a constitutional reform created a judicial council with the explicit aim of ending patronage and corruption within the judiciary