Is it possible that our results reflect differences across school districts that employ alternative grade configurations? We explore this question by conducting our test-score analysis separately for schools in Miami-Dade County. With more than 345,000 students, Miami-Dade is the largest district in Florida and offers a wide range of grade configurations for students up through grade 8. We find that the negative effects of entering a middle school for grade 6 or grade 7 are, if anything, even more pronounced in Miami-Dade County than they are statewide.
Recent studies have investigated retention in the context of state and district policies to require students to achieve a certain score for promotion. For example, Roderick and Nagaoka (2005) studied the effects of the Chicago Public Schools policy that bases promotion in grades 3, 6, and 8 on standardized test scores. Using comparison groups of students who just missed the promotion cutoff, these researchers found that 3rd graders struggled during the repeated year, had higher rates of special education placement, and two years later showed no advantage over those who had been promoted. Retained 6th graders had lower achievement growth than similar students who were not retained.