I’m finally reading the much-acclaimed “How Does Your Kindergarten Classroom Affect Your Earnings?” There’s no denying that it’s an extremely impressive piece. And unlike many of their fans, the authors are very careful. Note well: Project STAR was designed to test the effect of class size, not teacher quality. Now ponder these three quotes.
Quote #1 (from the abstract):
Class size does not have a significant effect on earnings at age 27, but this effect is imprecisely estimated.
Quote #2 (the actual magnitude):
Table V shows that without controls, students who were assigned to small classes are estimated to earn $4 more per year on average between 2005 and 2007. With controls for demographic characteristics, the point estimate of the earnings impact becomes -$124 (with a standard error of $336).
Quote #3 (the interpretation):
We conclude that the class size intervention, which raises test scores by 4.8 percentiles, is unfortunately not powerful enough to detect earnings increases of a plausible magnitude as of age 27.
READER COMMENTS
Kent Gatewood
Sep 28 2011 at 3:56pm
This explains a lot. I don’t got to kindergarten.
Andy
Sep 29 2011 at 1:21am
The difference between “small” and “large” classes is only 7 students (15 vs. 22 students). That doesn’t seem like a huge difference. I would expect a much bigger difference between classes of size, say, 40 and 5.
mark
Sep 30 2011 at 8:22am
One unstated and usually overlooked implication of that paper is that most teachers, i.e., those teaching anything other than kindergarten and those who are less experiecned kindergarten teachers, should be paid nothing above some bare babysitting minimmum as they add nothing to their students’ future earnings. That is obviously absurd which tells you how much value the paper has.
Mike Rulle
Sep 30 2011 at 4:05pm
I appreciate the authors writing this paper. The fact that it is useful to have been written is disturbing.
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