A signalling model of school grades under different evaluation systems

We examine the role of school grades as a signal of worker productivity under different examination systems in relation to errors that may affect student performance. Firms use school grades as a signal of workers’ effective skills, taking into account that these evaluations are effected by stochastic shocks. We show that more precise evaluation systems, being associated with a higher reactivity of wages to school grades, induce students to provide more effort. Low ability students tend to react less than high ability students. Moreover, individuals with low abilities may prefer less accurate evaluation systems. Nevertheless, when productivity increases, these systems become less convenient and the number of individuals preferring them diminishes. Our analysis highlights an important trade-off between centralised and decentralised evaluation systems. On the one hand, frequent evaluations, typical of decentralised systems, weaken the impact on grades of those errors which influence student performance and, so, reduce signal noise, while, on the other hand, different teachers generally adopt different performance assessment standards, leading to noisier evaluations.