IV-estimates of Class Size, Comparing Specifications
| Outcome [#pupils in current; #pupils in QJE] | Current (1) | QJE (2) |
|---|---|---|
| Cognitive ability, age 13 [N = 5,197; N = 5,116] | −0.0268** (0.0116) | −0.0330** (0.0146) |
| Non-cognitive ability, age 13 [N = 4,740; N = 4,681] | −0.0177 (0.0113) | −0.0265** (0.0118) |
| Academic achievement, age 16 [N = 5,400; N = 5,318] | −0.0267*** (0.0085) | −0.0233*** (0.0101) |
| Years of schooling, ages 27–42 [N = 5,669; N = 5,588] | −0.0318 (0.0234) | −0.0545* (0.0256) |
| P(Bachelor’s degree), ages 27–42 [N = 5,669; N = 5,588] | −0.0058 (0.0043) | −0.0076* (0.0043) |
| Earnings (%), ages 27–42 [N = 6,009; N = 5,920] | −0.0149** (0.0057) | −0.0117* (0.0061) |
| P(earnings >0), ages 27–42 [N = 6,009; N = 5,920] | −0.0035 (0.0022) | −0.0016 (0.0024) |
| ln(Wage), ages 27–42 [N = 3,227; N = 3,185] | −0.0065*** (0.0022) | −0.0063* (0.0033) |
| Number of districts × cohorts | 200 | 191 |
↵Note: The estimates are based on representative samples of individuals born in 1967, 1972, 1977, or 1982 in one-school districts. All ability measures are standardized. The educational outcomes are measured in 2009 while the labor market outcomes have been averaged over the 2007–2009 period. Earnings effects (and their standard errors) are divided by average earnings level to facilitate interpretation. The ln(wage) estimates are restricted to wage-earners. Average class size in Grades 4–6 is instrumented by indicators for being above first, second, or third threshold of the class size rule in Column 1. In Column 2, average class size in Grades 4–6 is instrumented by an indicator for being above any threshold of the class size rule. All models include the following controls for school district enrollment in grade 4: fixed effects for enrollment segment; linear controls for enrollment that are interacted with threshold. In Column 2, the controls for enrollment are also interacted with segment. In addition all models include the following baseline controls: municipality-by-cohort fixed effects, gender, dummy variables for month of birth, dummy variables for mother’s and father’s educational attainment, parental income, mother’s age at child’s birth, indicators for being a first or second generation Nordic immigrant, indicators for being a first or second generation non-Nordic immigrant, an indicator for having separated parents, and the number of siblings. Standard errors adjusted for clustering by enrollment count (84 clusters) are in parentheses. ***/**/* = the estimates are significantly different from zero at the 1/5/10 percent level, respectively.