Dr. Ehsan Latif and Dr. Stan Miles studied the factors affecting the academic performance of economics students at a small Canadian university using advanced statistical analysis. they found that graded homework, shown to have ambiguous effects in previous work, here had a positive effect !  A major contribution of the study is its analysis for various subgroups. Graded assignments had their strongest effects among male students and those with foreign (non-Canadian) backgrounds. GPA and higher levels of teacher  experience also positively affected performance. Their work got published in the Journal of Economics and Economic Education Research.