So, a few things going on here.
First, its kinda silly to take shots at an article for not controlling for enough relevant factors when you yourself are only controlling for one, being race. Krugman was writing an article for the general population, not an academic paper, so its held to a different standard. In my mind, the question is whether nor not Krugman misrepresented the situation, rather than whether or not he omitted controls. I'd argue that he didn't misrepresent the situation.
What could be driving the result were seeing? I think this is all consistent with Texas high schools being easier than national average. There are two ways you can evaluate the relative quality of the education there: look at factors that are known to correlate strongly with high school performance, and look at metrics that investigate post high school success. As Krugman says, Texas does very poorly on child health and wealth, which are known to correlated strongly with performance. Post high school, if you look at college graduation rates you see Texas does worse at all levels.
Jahoclave wrote:Besides if you observe romance, you change the outcome. Especially if you put his/her friend Catherine in a box.
Menacing Spike wrote:Was it the copper hammer or the children part that caused censoring?