The Lemann Center has just initiated a large, long-term research project using individual-level Prova Brasil data over a long period of time (2007-2017 and eventually, 1995-2017) to investigate a series of important questions about changes in student achievement. A partial list of these questions is: (a) the varying impact of student socio-economic background across municipalities and states, how this impact is changing over time, and the possible sources of these changes; (b) the relationship of test score gains by schools to location in municipalities and states making small and large test score gains over time, and the possible reasons for this relationship; and (c) the effects of school social class segregation, municipal poverty, and other social factors on the achievement of low-income and high-income students over time. The data set involves tens of millions of Brazilian students in fifth and ninth grades, and the research will contribute to a much more profound understanding of the changing face of Brazilian education, especially on what we can learn from variation across administrative entities. This will be a main priority for Lemann Center research in the next decade, and it will involve working with groups in Brazil, such as researchers at the Federal University of Minas Gerais, which has been involved in this type of research in recent years.