{"kind":"user","text":"Angrist and Lavy (1999), 'Using Maimonides' Rule to Estimate the Effect of Class Size on Scholastic Achievement', Table IV, column (1): for fifth-grade classes in 1991 (the full sample), estimate by two-stage least squares the effect of class size on the class's average reading comprehension score, using as the instrument the class size predicted by Maimonides' rule of 40 from the school's grade enrollment, with the percent of disadvantaged pupils as the only other regressor. Correct the standard errors for within-school correlation between classes. Report the coefficient on class size."}