ARI SHAPIRO, HOST:
The Los Angeles teachers' strike has now been going on for five days. The more than 30,000 public schoolteachers on the picket lines are demanding better pay, smaller classes and more counselors and nurses for students, among other things. Teachers have been pointing out that California spends less per student on public schools than many other states. We wanted to know how spending on education affects outcomes. So we've called on Kirabo Jackson of Northwestern University. He's a labor economist who studies education and social policy. Welcome.
KIRABO JACKSON: Hi. Thank you for having me.
SHAPIRO: You've looked at how increases in school spending influence how students do once they reach adulthood. So what have you found?
JACKSON: So the basic finding is that when children are exposed to increases in school spending while they're in school - so between the ages of 5 and 17 - they experience improved adult outcomes. So specifically, what we found was that increasing school spending by about 10 percent over a child's school-age years - if that child is low income, they experienced about a 13-percentage-point increase in the likelihood of graduating from high school. Their earnings were about 10 percent higher. They were about 8 percent less likely to be poor as adults even though they were poor as children.
And in some recent work, I've found that they're also less likely to be incarcerated as adults. I should be clear that there were also improvements for children who are not from low-income households, except their outcomes were not improved by as much.
SHAPIRO: Can you tell what the schools are spending that extra money on - like, what makes the most difference?
JACKSON: So most of the increases that school districts received tended to be spent on things like class-size reduction, increases in teachers' base salary, which is a way to attract and retain teachers. Some of it also went to increase in the number of support staff for students like counselors, people like that.
SHAPIRO: And to peel it back yet another layer, can you tell what happens when a school has better-paid teachers, smaller class sizes, et cetera, that makes a difference for these kids as they become adults?
JACKSON: So it's really hard to know specifically what individual component is doing the work. But we do know that when you have this sort of bundle of interventions, student outcomes improve. In terms of identifying those individual components, it's pretty hard. Having said, that there is research out there that I haven't been involved with myself documenting that students do have improved outcomes both in the short run and in the long run when they're exposed to smaller classes. And there's also good research out there showing that when you increase salaries, school districts are able to attract and retain higher-quality teachers, which, in turn, tends to be associated with improved outcomes.
SHAPIRO: Now, you said your research shows that there are measurable benefits from a 10 percent increase in spending. What about a 5 percent or a 2 percent increase in spending? Does it stand to reason that any increase will have some benefit?
JACKSON: So the basic 10 percent number comes from the fact that much of the increases that we studied happened due to school finance reforms or legislative reforms that suddenly and in unanticipated way increased the revenue sources for low-income school districts or districts that were not spending very much. And a typical size of that increase was about 10 percent. My sense is that these things tend to be nonlinear. And so it's probably unlikely that a 20 percent increase would be twice as large as a 10 percent increase.
SHAPIRO: To bring this back to the strike in Los Angeles, the school district has suggested taking money away from a teacher pay raise and using it to do other things like provide for counselors and reduce class sizes. Does your research show whether that would have a positive impact?
JACKSON: That is a good question. And it's actually a very difficult question to answer. So the short answer is, I don't know. My general feeling is that when school districts are strapped for cash, there's always something that they're not spending enough on. It might be things like making sure the area is sufficiently air-conditioned. It might be making sure teachers get sufficient pay. It might be making sure that they have enough textbooks for the children. Each one of those things is potentially important.
And when you're in a scenario where you're sort of underutilizing a particular input, putting money into that input could have really, really, really large positive impact. So in a scenario where districts are strapped for cash, I sort of leave it up to the wisdom of those individuals on the ground to figure out how to allocate those funds the most effectively. It is hard for a researcher to make that determination.
SHAPIRO: Kirabo Jackson is a professor of human development and social policy at Northwestern University. Thank you.
JACKSON: Thank you so much. Transcript provided by NPR, Copyright NPR.