Overall, our results consistently indicate that the increased focus on individual teacher performance caused a sizable and statistically significant decline in student achievement. This decline in achievement is also much more pronounced in the case of national exams with an effect of up to 40% of a standard deviation. As in the different effects in terms of internal and external results, our triple-difference evidence also documents a significant increase of grade inflation. In addition, in support of a causal interpretation of our results, we also find that in almost all specifications and dependent variables there are no significant differences between the treatment and control groups over time before the introduction of merit-pay. Finally, the inclusion of different control variables or the consideration of different subsets of the data makes only very minor differences to the size of our estimates, as would be the case if assignment to treatment were random.
In 2007 Portugal instituted a merit pay plan. Azores and Madeira (the graph above) and private schools were excluded. Using these as a control, the quoted study found that this merit pay plan resulted in a decline is student achievement.
Arne Duncan and Barack Obama have made incentive pay plans a centerpiece of their “Race to the Top” scheme. It may be a path to the bottom.
More on the “Race to the Top” later this week.
Thomas J. Mertz