Table S4.

Regression results

Variable	1	2	3	4	5	6	7
testhour	−0.159***				−0.127***	−0.226***	−0.236***
	(0.038)				(0.036)	(0.023)	(0.022)
break					0.691***	0.534***	0.487***
					(0.188)	(0.075)	(0.071)
9		−1.353***	−1.069***	−0.978***
		(0.247)	(0.111)	(0.106)
10		−0.983***	−0.788***	−0.749***
		(0.149)	(0.094)	(0.090)
11		−1.556***	−1.470***	−1.392***
		(0.250)	(0.123)	(0.118)
12		−0.844***	−1.130***	−1.124***
		(0.190)	(0.114)	(0.110)
13		−1.077***	−1.463***	−1.524***
		(0.305)	(0.165)	(0.157)
Fixed effects included	No	No	Yes	Yes	No	Yes	Yes
Individual controls	No	No	No	Yes	No	No	Yes
Number of schools			2,028	2,028		2,028	2,028
Smallest group			2	2		2	2
Largest group			3,984	3,984		3,984	3,984
F-value th9 = th10..= th13 = 0		11.711	36.617	37.727
P value th9 = th10..= th13 = 0		0.000	0.000	0.000
Model degrees of freedom		5	20	30	2	17	27
Adjusted R2		0.00	0.00	0.08	0.00	0.00	0.08
AIC	19,460,401	19,459,913	19,320,488	19,149,059	194,601,29	19,3205,44	19,149,447
Observations	2,034,964	2,034,964	2,034,887	2,034,887	2,034,964	2,034,887	2,034,887

Dependent variable: test score percentiles. All estimates are obtained using OLS. Column 1 shows the point estimate for ${\alpha }_1$ from estimating model S1. Columns 2–4 show results from estimating model S2 using ordinary least squares. Columns 5–7 show results from estimating model S3 using ordinary least squares. The table only shows the point estimates for the coefficients ${\alpha }_1-{\alpha }_5$ in model S2 and coefficient ${\alpha }_1$ and ${\alpha }_2$ for model S3. Columns 2 and 5 show results from estimating models without any control variables. Columns 3 and 6 show results from estimating simple models with only school, year, day of the week, grade, and subject fixed effects. Columns 4 and 7 show results from estimating the full models without individual fixed effects. SEs clustered at the school level are shown in parentheses. Number of schools show the number of schools included and thus also the level of fixed effects and clustering. Smallest/largest group shows the smallest/largest number of observations from one school. F-value gives the F-statistic for a test of joint significance for the hourly indicators, and P value gives the corresponding P values. Model degrees of freedom specifies the number the degrees of freedom used by the model. AIC gives the Akaike information criteria. Smaller AICs are generally preferred. Observations refers to the number of observations included in the regressions. The dependent variable is test score percentile rank (1–100) within the test year, grade, and subject cell. As fixed effects on the school level implies comparisons within schools, we only include schools with at least two tests. Regressions are based on administrative data from Statistics Denmark and the Danish Ministry for Education, for all mandatory tests 2009/10–2012/13.

^***P < 0.01; **P < 0.05; *P < 0.1.