Economists regularly regress IQ scores or achievement test scores on covariates, for example to evaluate educational policy. These test scores are ordinal measures, and their distributions can take an arbitrary shape, even though they are often constructed to look normal. The ordinality of test...

In this paper, I manly seek to test the robustness of Hanushek et al.'s (2013) hypothesis, according to which the impact of autonomy in terms of learning outcomes differs across levels of development, being positive for developed countries but not for developing countries. I do so by...