You sometimes hear education reformers say that teacher quality is the number one statistical correlate of measurable student learning. This is wrong. Parental socioeconomic status, as measured in a variety of different ways, is far and away the biggest correlate of student achievement. Teacher quality is the most important in-school factor, but out-of-school factors still have a bigger correlation.
I find that this is widely misinterpreted by people as knock-down evidence that raising the incomes of poor parents is the best way to improve student learning. Common sense suggests otherwise. My father dropped out of high school in the middle of 10th grade. As it happens, my father went on to have a successful career as a novelist and screenwriter and is by no means poor. Still the fact of the matter is that my mother could help me with my high school math homework and my dad couldn’t, since he has very little formal math education. A person who grows up in a household headed by a single mother who didn’t complete high school is going to be at a significant educational disadvantage vis-a-vis a person who grows up in a household with two college educated parents for reasons that are not going to be solved by a transfer of financial resources to the single mother. Similarly, a person whose parents were both raised in Latin America and don’t speak English is going to be at a substantial disadvantage. Literate English-speaking parents do a lot to teach their kids to read and write, parents who don’t speak English and may have limited literacy in their native language aren’t able to do this.
There are very good reasons to transfer money to poor parents — alleviating poverty is a freestanding good thing to do — but lack of money per se plays a limited role in why low-SES children have trouble in school.
Which isn’t to say that social policy factors are irrelevant. Spending more money on lead abatement is an excellent idea. Improving poor children’s access to health care should be an important priority. But here again note that the Dread Evil Neoliberal School Reformer Barack Obama And His Lackeys At The Center For American Progress can hardly be accused of inaction on this front. By the same token, we have specific evidence that better nutrion helps improve learning. But the proximate obstacle to improving the nutritional content of school lunches is the Potato Lobby not education reformers.
Even if you solved those problems, you’d still be left with the reality that poor children tend to have poorly educated parents who have less ability to help them with formal and informal learning. There’s probably no way to fully equalize this issue, short of something like Plato’s scheme to raise children in communal centers. But to a first approximation, the issue is that poor kids need great teachers.