School privatization has some wicked confounds for any claims of success because it&#x27;s almost impossible to do a true randomized trial. In many cases, the reported success is due to cherry-picking the best students; in others, the lead disappears over time as regression to the mean takes effect as a school&#x27;s population grows large enough to average out a few stellar performers. The really positive news coverage almost universally neglects to make any attempt to do a demographically-matched comparison and in most cases the effect disappears once you control for poverty, family stability, etc.<p>This isn&#x27;t to say that charter schools are cheating, only that something this complicated is easy to misunderstand. It&#x27;s also important to look at other trade offs: perhaps a school&#x27;s performance is actually due entirely to attracting students who would be successful almost anywhere – a city is almost certainly better off if they stay there rather than moving to a nearby suburb, even if that doesn&#x27;t directly help with the question of how to help disadvantaged kids.