Investigation of peer effects on achievement with sample survey data on schools may mean that only a random sample of the population of peers is observed for each individual. This generates measurement error in peer variables similar in form to the textbook case of errors-in-variables, resulting in the estimated peer group effects in an OLS…

The article considers a test of specification for quantile regressions. The test relies on the increase of the objective function and the worsening of the fit when unnecessary constraints are imposed. It compares the objective functions of restricted and unrestricted models and, in its different formulations, it verifies (a) forecast ability, (b)…

There are large differences across countries in instructional time in public schooling institutions. For example, among European countries such as Belgium, France and Greece, pupils aged 15 have an average of over a thousand hours per year of total compulsory classroom instruction while in England, Luxembourg and Sweden the average is only 750…