The authors analyze the effect of school, student, and teacher charact
eristics on teacher effort, as measured by homework frequency and time
put in at home. Although teacher autonomy and ''professionalism'' hav
e little effect on effort, teachers' academic backgrounds matter. Teac
hers who are assigned higher-achieving students also put in more effor
t, a response to student ability as well as a consequence of staffing
such classes with harder-working instructors.