Ryan Avent responds on teacher's unions:
Things in New Orleans have improved. But they remain terrible. What’s more, too many institutional factors changed for us to have a good idea what generated the improvement. And statisticians out there might note that when tracking changes over time, it helps to keep the sample constant. For an economist to look at a city’s educational system, subtract a quarter of a million poor people, then look at it again and suggest that destroying the teachers’ unions made all the difference is…well it’s not exactly a rigorous analysis.
For my money, the best new research on this subject emphasizes the role of parental skill levels in achievement and the importance of investment in disadvantaged children when they’re young. Union busting is a waste of time; it’s like changing the oil on a car missing a wheel and hoping for huge performance improvements.
I agree that there's a sample problem, but it also seems that more kids in New Orleans now are qualifying for free lunch than did before, so I'm skeptical that this explains the change. Also, the test scores improved from 2007 to 2008. And the pattern of improvement--strongest in the younger grades--is what you'd expect if the school were the major factor rather than the demographics.
I'm familiar with the research on parental skills and early childhood intervention. I just don't know what to do with it. So far I have not seen a single successful early childhood intervention that is even arguably scaleable: you're talking about intensively monitored programs using top-notch personnel, all of whom are deeply committed to the project's goals and procedures. The longest data set we have is, AFAIK, the Perry Pre-School Project, which produced exceedingly modest gains for a pricetag of more than $20,000 per child per year in today's dollars. Again, that's with a small program of highly committed staff.
What we got instead was Head Start, which produces small gains that most evidence suggests disappear a few years after the kids exit the program. Even if we wanted to do Perry Pre-School, or something even better, nationwide, where would we find the staff? Pre-K sounds great, but it's very likely to be slightly glorified baby sitting outside of affluent school districts that don't need it in the first place.
Since we're not (I hope) going to take kids out of the disadvantaged homes they are born to, the schools are what we're stuck with. And there are programs that work--at least, better than what we have now. They just bore the hell out of the teachers.
I'm not against early childhood intervention, if it works. But it's not going to save us from having to teach the kids better in grades 1-12.