Do teaching evaluations lead to lower standards in class?

In the somehow recent past, teaching evaluations have become obligatory in many universities/departments in Germany. I've also heard that sometimes these evaluations are used in formal ways to decide about salary raises or even hiring. For me it is pretty clear that a purely formal use of teaching evaluations is not a good idea, but my questions goes in a different direction. From time to time I read in newspapers and other kind of media that a side effect of these teaching evaluations is that

"the solicitous professor who aims at good teaching evaluations usually lowers the level in class and gives good grades in general."

Myself I never did it like that and I have the feeling that giving an "easy" course where everyone is able to score good grades but does not learn very much will not be appreciated by the students.

My questions is:

Do you know of any evidence for the claim that teaching evaluations encourage professors to lower standards and give better grades?

Note that I am not trying to deduce that the use of teaching evaluations in a formal way to decide about hiring or salary is a good thing; I am just not sure that "lowering standards and pampering students" is a major side effect of teaching evaluations.

Answer

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.