Cognitive scientist Dan Willingham has a helpful column on the WaPo’s “Answer Sheet” blog. In it, he notes that DC Public Schools advises its employees to teach to students’ “diverse learning styles” (e.g. “auditory learners,” “visual learners,” etc.) despite the fact that research shows these categories are pedagogically meaningless.

But what really grabbed my attention was this comment: “a misunderstanding of a pretty basic issue of cognition is a mistake that one does not expect from a major school system. It indicates that the people running the show at DCPS are getting bad advice about the science on which to base policy.”

As cognitive scientists have been collecting and analyzing evidence on “learning styles” for generations, social scientists and education historians been doing the same for school systems. What these latter groups find is that it is perfectly normal for public school districts to be unaware of or even indifferent to relevant research and to make major pedagogical errors as a result. Furthermore, there is no evidence that large districts are any better at avoiding these pitfalls than smaller ones. If anything, the reverse is true.

Not only are such errors to be expected of public school systems, we can actually say why that is the case with a good degree of confidence: public schooling lacks the freedoms and incentives that, in other fields, both allow and encourage institutions to acquire and effectively exploit expert knowledge.

Districts such as Washington DC can persist year after year with abysmal test scores, abysmal graduation rates, and astronomical costs. That is because they have a monopoly on a vast trove of government k‑12 spending. In the free enterprise system, behavior like that usually results in the failure of a business and its disappearance from the marketplace. So, in the free enterprise sector, it is indeed rare to see large institutions behaving in such a dysfunctional manner, because it would be difficult if not impossible for them to grow that big in the first place. Long before they could scale up on that level, they would lose their customers to more efficient, higher quality competitors.

So if we want to see the adoption and effective implementation of the best research become the norm in education, we have to organize schooling the same way we organize other fields: as a parent-driven competitive marketplace.