Lowering class sizes for elementary students in California — a controversial move that has received a lukewarm reception in some prominent research studies — resulted in greater learning gains than previously thought, according to a new study published by the National Bureau of Economic Research.

In addition to the positive impact of studying in smaller groups, students benefited from the migration of new classmates who were drawn in from area private schools by the promise of a lower student-teacher ratio.

The paper’s authors acknowledge the high dollar value of California’s reform ($650 per student provided by then-Gov. Pete Wilson, enough to entice almost every school district in the state) but maintain that the policy’s most striking benefits lay in changing the demographics of many public elementary schools across the state.

The flow of would-be private school students into public elementary schools resulted in a swift demographic change in classrooms, which suddenly welcomed thousands of whiter, more affluent students. Their presence resulted in higher average test scores, but also helped improve their classmates’ performance as well, the authors said.

Read the full article about reducing class sizes by Kevin Mahnken from The 74.