Do teaching evaluations lead to lower standards in class?
Jacob and Levitt have an article in the quarterly journal of economics that looks at teachers cheating in public schools due to compensation based on their class performance. They find that teachers will do things to help their students get higher grades if it effects their compensation.

Rotten Apples: An Investigation of the Prevalence and Predictors of Teacher Cheating. Quarterly Journal of Economics. 2003

An article by Nelson and Lynch look at the relationship between grade inflation and teaching evaluations suggesting professors buy better teacher evaluations with grades.

Grade Inflation, Real Income, Simultaneity, and Teaching Evaluations. The Journal of Economic Education. 1984.