Working longer makes students stronger? The effects of ninth grade classroom hours on ninth grade student performance

Background

Despite much discussion on the role of education policy on school and student performance, we know little about the effects of school spending at the margin on student cognitive achievement beyond the effects of class size.

Purpose

The paper examines the effects of annual ninth grade classroom hours in literacy and maths on ninth grade (aged 16) student performance in writing and maths, respectively.

Programme description

In Denmark, primary school consists of the first to the ninth grades. Before 2003, only few national regulations governed classroom hour administration in public primary schools, resulting in large variations in the number of classroom hours across the country. Thus, following national discussions about improving skill formation in a heterogeneous student body, in July 2003 the Danish Ministry of Education made changes to classroom hour planning that immediately reduced variation in classroom hours across schools.

Sample

I use a sample of 64% of all ninth grade students (aged 16) in Denmark in 2003–2006, equivalent to 144,739 students and 921 schools (58%) for literacy and 144,618 students and 924 schools (58%) for maths. Using data from administrative records from various registers and through unique personal and institution identifiers, I first link school characteristics to the students and, second, link students to a long list of individual and parental background characteristics.

Design and Methods

The paper exploits the unique policy-induced variation in classroom hours in a one-year period before and a three-year period after the reform. As Danish municipalities are the local school authorities and as the reform narrowed the gap in classroom hours across them, the municipalities experienced differences in intensity to treatment. Thus I use a school fixed-effects model, where an interaction-term between the continuous treatment – classroom hours – and the year of policy implementation define the effects of classroom hours in literacy and maths on student achievement in writing and maths, respectively.

Results

On average, the reform changed classroom hours by 2.2–3.3% in literacy and maths, with an impact on student achievement. For literacy I find no significant effects of classroom hours, but for maths I find stronger effects. One additional hour per year increases the maths score by 0.21% of a standard deviation, decreases the probability of obtaining a test score below the mean by 0.01%, and increases the probability of obtaining a test score above the mean by 0.08%. One possible explanation for this difference between subjects is that training in literacy takes place in the home environment more than maths and thus is less sensitive to classroom hour changes.

Conclusions

The findings are considerably important when placed in the context of debates about intra-school resource allocation. In maths, classroom hours changed on average only by 2.63 annual hours from 2003 to 2004. However, I still find effects of these generally small changes to classroom hours; thus student achievements are sensitive to even small changes in classroom hours.

Keywords:

• cognitive achievement
• school resources
• natural experiment

Notes

1. The changes to classroom hours constitute the primary but not sole amendment in the CHR. Before the reform, the DME recommended curriculum standards, which the CHR also formalised. However, as most municipalities already followed these guidelines (Jess and Hansen 2005), the correlation between differences in classroom hours and curriculum standards is not likely to affect the results.

2. This and the following Web Appendix Tables and Figures are available online.

3. Appendix Figure A1 illustrates similar graphs for the seventh and eighth grades.

4. The model exempts past-pupil achievement because only one national test exists in Danish compulsory schooling (until 2010).

5. However, Heinesen and Graversen (2005) find that increasing per student expenditure by 10% increases the probability of completing secondary school by only 1%.

6. As schools must provide after-school care from grades zero to five, the investigated cohorts are not affected by changes in budget reallocation to these institutions.

7. A few pupils are older or younger at school start (mainly December or January births). As age at testing is likely to affect performance, I control for age at testing measured in months in the model.

8. Rangvid (2002), after controlling for parental background, shows that no significant differences in student achievement exist between private and public school students.

9. The effect in writing is 0.0016 (0.0011) and the effect in maths is 0.0034 (0.0013). I include covariates in these estimations. See Appendix Table A4 for the full list of covariates.

10. Ideally I should investigate the effect of a cohort’s first to ninth grade classroom hours on student performance, because such an investigation takes classroom hour redistribution amongst grades into account (e.g. a transfer from earlier to later grades). Unfortunately, in such an investigation, the Danish data is likely to generate biased effects of classroom hours for two reasons. First, data on classroom hours begin in 2002 (i.e. two years before the reform). Therefore, an investigation of first to ninth grade would rely heavily on the assumption that the number of first to seventh grade hours for the school years 1995–2001 would be the same as first though seventh grade classroom hours in 2002. Second, the first cohort fully affected by the reform (enrolled 2004–2012) experienced several other institutional changes. For example, DME amended the Primary School Act in November 2006 (Ministry of Education 2006). Amongst other things, the 2006 Act introduced ‘individual learning plans’ for each student. An individual learning plan includes information about the student’s current level of proficiency, short-term learning goals and plans for reaching these goals. The plan is a tool for maintaining a focus on progress for each student and for enhancing teacher–parent communication about learning progress. Although the initial investigation of these individual learning plans did not focus on improvement in student performance, the authors find that the learning plans improved student motivation and the teacher–parent communication (EVA 2008). Thus the plans can potentially affect student performance in the long run. Another important institutional change was the 2006 municipality reform: from January 2006, the 271 municipalities were collapsed into 98. For many schools this change meant that after a year or two their local school authority had changed.

11. For both subsamples, the group of municipalities with no classroom hour changes are included in the reference group.