Noah Smith:

The case against spending more on schools comes in two basic forms. One is to look at various U.S. states, and see whether the ones that spend more on education enjoy better outcomes. This has been done many times, with decidedly mixed results. Some studies show little state-by-state correlation between spending levels and educational performance, while others show a fairly substantial one.

The second case against increased spending comes from looking at correlations across time. If more money is better, we’d expect to see increases in school funding followed by improvements in performance. In fact, though public school spending has increased a lot in the past couple of decades, achievement hasn’t really increased much.

So with mixed evidence from state-by-state analysis and discouraging evidence from the history of spending increases, many people are ready to conclude that throwing more money at education is a losing battle. Some spending opponents place their hopes in charter schools and other reform efforts, while others claim that education just doesn’t work — that academic ability is either innate or learned from an early age.

Kansas City dramatically increased spending years ago, and……