Table 4 The Effect of Class Size in Primary School (PS) and Middle School (MS) on Average Outcomes, Ages 27−42, Combined Schools
SchoolingLog-EarningsEarnings
Panel A: First Stage, PS
Above PS threshold

–5.66**

(0.38)

–5.69**

(0.37)

–5.66**

(0.37)

Above MS threshold

–0.93**

(0.24)

–0.94**

(0.24)

–0.93**

(0.24)

F-test PS instrument227232234
F-test MS instrument151515
Panel B: First Stage, MS
Above PS threshold

–0.72**

(0.28)

–0.74**

(0.27)

–0.75**

(0.27)

Above MS threshold

–7.97**

(0.29)

–8.04**

(0.28)

–7.99**

(0.28)

F-test PS instrument778
F-test MS instrument774820801
Panel C: Reduced Form
Above PS threshold

0.018

(0.040)

–0.006

(0.008)

–0.016

(0.010)

Above MS threshold

0.011

(0.033)

0.001

(0.005)

0.003

(0.007)

Panel D: 2SLS
Average class size, Grades 1–6 (PS)

–0.0017

(0.0068)

0.0015

(0.0014)

0.0029

(0.0019)

Average class size, Grades 7–9 (MS)

0.0003

(0.0039)

–0.0002

(0.0007)

–0.0006

(0.0009)

N schools682682686
N students162,104163,785171,174
  • Notes: Estimates for the sample of students who graduated from a combined school, 1978–2001. The schooling outcome is defined as years of educational attainment, log-earnings is the log of (positive) yearly earnings, and earnings is the yearly earnings relative to the average earnings of the cohort of compulsory school graduates. All outcomes are measured when the individuals are 27–42 years old. The regressions control for segment and segment-specific linear splines in both primary school and middle school enrollment. The primary school controls are interacted with maximum class-size regime. All regressions also include year of graduation fixed effects, individual background controls for gender, parental education, immigrant background, month of birth, and age at graduation. Standard errors clustered at the school level are reported in parentheses. *p < 0.10, **p < 0.05.