Working Paper: NBER ID: w20173
Authors: Joshua D. Angrist; Erich Battistin; Daniela Vuri
Abstract: An instrumental variables (IV) identification strategy that exploits statutory class size caps shows significant achievement gains in smaller classes in Italian primary schools. Gains from small classes are driven mainly by schools in Southern Italy, suggesting a substantial return to class size reductions for residents of the Mezzogiorno. In addition to high unemployment and other social problems, however, the Mezzogiorno is distinguished by pervasive manipulation of standardized test scores, a finding revealed in a natural experiment that randomly assigned school monitors. IV estimates also show that small classes increase score manipulation. Estimates of a causal model for achievement with two endogenous variables, class size and score manipulation, suggest that the effects of class size on measured achievement are driven entirely by the relationship between class size and manipulation. Dishonest scoring appears to be a consequence of teacher shirking more than teacher cheating. These findings show how consequential score manipulation can arise even in assessment systems with few NCLB-style accountability concerns.
Keywords: class size; moral hazard; score manipulation; education policy; Italy
JEL Codes: C26; C31; I21; I28; J24
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| class size (C55) | student achievement (I24) |
| class size (C55) | score manipulation (C87) |
| score manipulation (C87) | student achievement (I24) |