Discussing class size is an important concern for policy makers since it affects the government’s spending on education and the increase in human capital, that is, the increase in the supply of better-educated individuals (smaller class sizes are generally perceived as allowing teachers to spend more time with each student, thus providing a better performance) – I will be referring to primary and secondary education mostly, which is also the focus of PISA’s tests and reports. It is also a challenging topic since it is difficult to decide on how big an improvement in student performance (and on subjects such as criminality rates and health issues) should be to justify the cost.
First of all, we must bear in mind PISA reports state that a smaller student/teacher ratio is not, on its own, a sufficient policy device to improve the performance of education systems, and is a less efficient measure than increasing the quality of teaching, and evidence shows that there is a large range of class configurations within the OECD countries with very different student performances (see also Ehrenberg, et al., 2001, and Piketty, 2006). On the other hand, Krueger (2002) find evidence that it is an effective measure for certain groups, such as those from disadvantaged backgrounds, and Jepsen and Rivkin (2009) find evidences that smaller classes raise mathematics and reading achievements.
In Portugal, due mostly to austerity measures, which are evidently influenced by the government’s political views, – including salary cuts for personnel working in public education, the freezing of career progression in public service, fewer posts in school management, a downsizing of regional administration for education, and a major rationalization of Ministry services that led to a restructuring of its organization – the tendency has been to increase the class size.
Portugal’s average class size has not changed from 2000 to 2011. Yet, in more recent years, there has been a slight increase, to 26 students per class in primary education and 30 in secondary. The opposition parties alerted that the measure should not be undertaken since PISA’s Education at a Glance showed Portugal’s PISA scores were below the OECD average and they defended class size was one of the causes for that.
To determine what class size is ideal will always be an uncertain chore since it is difficult to assess whether the increase in educational costs will equalize the increase in society’s welfare that will occur when one decreases class size. Moreover, the discussion will always have an ethical and political side that impacts the policy maker’s decision – how much is providing education an “obligation” of the government? Should we focus on student performance considering education plays a relevant role not only in productivity but also on social cohesion?
However, in a time when government spending plays such a relevant role in policy decisions, reducing classes will probably not be the most effective measure, since research has generally found it is not the best approach to increase student performance.
Ehrenberg, R., et al. (2001), “Class Size and Student Achievement”, Psychological Science in the Public Interest, Vol. 2, No. 1, pp. 1-30.
Jepsen C. and Rivkin, R. (2009), “Class Size Reduction and Student Achievement: The Potential Tradeoff between Teacher Quality and Class Size,” Journal of Human Resources, University of Wisconsin Press, vol. 44(1).
Krueger, A.B. (2002), “Economic Considerations and Class Size”, National Bureau of Economic Research Working Paper: 8875.
Piketty, T. and M. Valdenaire (2006), L’Impact de la taille des classes sur la réussite scolaire dans les écoles, collèges et lycées français : Estimations à partir du panel primaire 1997 et du panel secondaire 1995, ministère de l’Éducation nationale, de l’Enseignement supérieur et de la Recherche, Direction de l’évaluation et de la prospective, Paris.
Ana Martins, 734