I will measure the degree to which rights and obligations are made effective in Brazil, Argentina and Costa Rica, and explore possible causes for the failure of certain systems to make formal laws effective. I argue that what we observe in many countries in Latin America is the presence of a legal system that has universal laws at the formal level, but an informally institutionalized expectation that the laws will be applied or enforced in personalistic ways. I argue that such a system requires people to produce something in addition to their legal rights in order to prevail on their claims or have their rights respected. To identify what it is that is required in addition to rights, I will conduct interviews of the people who attempt to make the system work for their clients (advocates who process claims through bureaucracies and courts), as well as analyzing a random sample of cases in a specific area of the law to test for the presence of informal exceptions to the rules. Once I have mapped these informal institutions, I will explore the possible causes that lead to different levels of the rule of law in different systems.