This paper is based on two independent studies conducted by Rodrigues (2009) and Guimarães (2010). These studies examined intertemporal changes with respect to two educational dimensions: academic achievement and grade progression probability, in Brazil. They employed two distinct databases (SAEB and PNAD) and also two distinct methods (counterfactual decomposition and school transitions models). In both studies, the year of 1999 drew attention because of a throwback in terms of average achievement and low chances of progression. The results show that the effects of student social origins explain a large amount of the low educational outcomes (both achievement and inequality of opportunity) observed in this period and suggest the existence of an interrelationship between achievement and school flow