tag:blogger.com,1999:blog-2830084253401570472.post192593356936358439..comments2024-03-28T09:22:36.967+13:00Comments on Offsetting Behaviour: Charter SchoolsEric Cramptonhttp://www.blogger.com/profile/15831696523324469713noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-2830084253401570472.post-56787849136338197432011-12-07T09:49:28.159+13:002011-12-07T09:49:28.159+13:00Then you want to read Roland Fryer's work on t...Then you want to read Roland Fryer's work on the characteristics of good charter schools.Eric Cramptonhttps://www.blogger.com/profile/15831696523324469713noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-37798794998873524792011-12-07T09:36:27.133+13:002011-12-07T09:36:27.133+13:00In my casual, sporadic reading of the charter scho...In my casual, sporadic reading of the charter school lit, it seems like sometimes they are positive and sometimes not, in some places for some pupils. So, the policy question facing us isn't 'are they good?', but 'how do we make them good for these pupils?'<br />That is, if we want to make schools good for children, rather than sacrificing them on the altar of [fill in the blank].Billhttp://nzier.org.nz/user/billkaye-blakenoreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-79244541915476800212011-12-07T09:25:54.223+13:002011-12-07T09:25:54.223+13:00@Matt: There are tons of studies showing little ef...@Matt: There are tons of studies showing little effect, tons of studies showing very heterogeneous effects (some charters are great, others not). But it's damned hard to draw conclusions out of the literature. Why?<br /><br />1. A bunch of these studies are hit pieces funded by the teachers' unions and need to be treated with caution;<br /><br />2. Parsing out effects is a nightmare. Even the quasi-experiments above aren't perfect; Lemmus lists some of the potential reasons. I worry less about the peer effects one than he does because that's one of the points of Charters - that they can and do kick out students who are disruptive and make sure that they can't wreck other students' experiences.Eric Cramptonhttps://www.blogger.com/profile/15831696523324469713noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-83592031656510397342011-12-07T09:03:46.315+13:002011-12-07T09:03:46.315+13:00I haven't got an opinion on charter schools, b...I haven't got an opinion on charter schools, but as far as I can tell their desirability remains an empirical question - and so far you're the only person to put up any evidence.<br /><br />Until the people who keep posting newspaper articles that don't like the schools actually start showing real evidence of their position, I'm not going to complain about the schools being trialed.Matt Nolanhttps://www.blogger.com/profile/05615455113796090765noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-22664674369335505352011-12-07T08:18:23.268+13:002011-12-07T08:18:23.268+13:00Yup, exit options, even if not exercised, must mat...Yup, exit options, even if not exercised, must matter a lot. As for the best point in the links, I would guess that it's the point about peer effects. To simplify, if there were only two kinds of students, "motivated" or "not motivated", I would not be surprised about huge effects on a student in question of whether he's in a class with 80% or 20% motivated other students.LemmusLemmushttps://www.blogger.com/profile/00917054221547240969noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-11956502416429367192011-12-06T22:08:10.604+13:002011-12-06T22:08:10.604+13:00@Lemmus: Read the last paragraph of this piece esp...@Lemmus: Read the last paragraph of this piece especially for how charters can increase average teacher quality system-wide.<br />http://www.city-journal.org/html/13_1_how_i_joined.htmlEric Cramptonhttps://www.blogger.com/profile/15831696523324469713noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-91453442183620495202011-12-06T21:54:47.285+13:002011-12-06T21:54:47.285+13:00@Lemmus: It scales to the extent that charters are...@Lemmus: It scales to the extent that charters are able to draw better talent into teaching. I've seen decent argument that the current system doesn't do well on that front.<br /><br />But you're right on Psycho's point - I got that wrong. I'm not sure how big an effect it would be, but definitely doesn't attenuate the measured effects.<br /><br />The best point, I think, in the two links you sent is the non-random selection of which schools wind up being the ones running lotteries; that would mean results are limited to those schools able to emulate what that cohort of schools is doing. It doesn't cut against the point that charter schools' success results from more than just selecting the best incoming students, unless your linked anecdote is widespread practice, but it does suggest that adding up across those students is a high upper bound on system gains. Unless other schools are able to emulate the successes of the best schools (which, I think, is part of Hoxby's point)Eric Cramptonhttps://www.blogger.com/profile/15831696523324469713noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-24570977257918757472011-12-06T20:52:11.708+13:002011-12-06T20:52:11.708+13:00Eric: I haven't read the links, but I didn'...Eric: I haven't read the links, but I didn't find your reactions to the commenters above all that convincing.<br /><br />If Kimble's first point is right (teachers at charter schools are of above average quality), this means that positive results shouldn't be expected to scale up, unless you think that the nationwide introduction of charter schools would magically improve average teacher quality.<br /><br />If by attenuation bias you mean bias towards zero introduced by random noise in the predictor variable, that doesn't describe Psycho's point at all. Rather, his point (if I understand it correctly) is that treatment is confounded with parent enthusiasm/disappointment and that effects of the latter would incorrectly be ascribed to treatment in these designs. One might also tell the opposite story (lottery winning parents scale down their own efforts to help their children, etc.), but it's certainly a point worth considering.<br /><br />Perhaps also of interest, <a href="http://morethoughtful.blogspot.com/2009/09/what-is-gold-standard.html" rel="nofollow">here</a>'s a post on such studies' limitations and <a href="http://isteve.blogspot.com/2009/03/how-random-is-admission-to-charter.html" rel="nofollow">here</a>'s an anecdote about how "random" assignment may not actually be random.LemmusLemmushttps://www.blogger.com/profile/00917054221547240969noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-19871852044505162792011-12-06T13:58:13.170+13:002011-12-06T13:58:13.170+13:00@Eric: mmm, maybe it is evidence of the opposite?@Eric: mmm, maybe it is evidence of the opposite?Kimblenoreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-72187913519747083322011-12-06T13:10:32.086+13:002011-12-06T13:10:32.086+13:00@Kimble: I don't think that's evidence aga...@Kimble: I don't think that's evidence against charter schools' efficacy.<br /><br />@Psycho: Unclear that that isn't just attenuation bias.Eric Cramptonhttps://www.blogger.com/profile/15831696523324469713noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-81683957213636473622011-12-06T11:27:47.235+13:002011-12-06T11:27:47.235+13:00There are ways of controlling for selection effect...<i>There are ways of controlling for selection effects. Here's Josh Angrist and coauthors from 2009, HT: Marginal Revolution. They used a lottery as random assortment mechanism: Boston charter schools were oversubscribed, so a lottery was used to determine which kids got in. So Angrist can compare those who won lotto with those who didn't.</i><br /><br />There are ways of <i>attempting</i> to control for selection. In this case, the lottery losers presumably had parents who were motivated and keen to get them out of the public school system and who also presumably were profoundly disappointed that their kids were rejected back into a school system they fully expected to do a poor job. The lottery winners' parents presumably were also motivated and keen to get their kids out of the public school system, felt like they were making a fresh new start on the road to educational success and sent their kids off in the full expectation that they were going to do well. If Angrist has a way to control for that, his paper would be very interesting.Psycho Milthttps://www.blogger.com/profile/00779500926576047736noreply@blogger.comtag:blogger.com,1999:blog-2830084253401570472.post-9873053411094165442011-12-06T11:01:28.204+13:002011-12-06T11:01:28.204+13:00I think DiM may be right in identifying selection ...I think DiM may be right in identifying selection bias as the cause for the different results.<br /><br />The teachers selected by charter schools (or more likely, teachers who select charter schools as a place to work) are probably better than average.<br /><br />And the leaders of charter schools probably select a better than average expenditure plan.Kimblenoreply@blogger.com