There are some researchers who believe there is a correlation between spending more money and improving student outcomes, and there are many others who strongly disagree. But most of those who believe in correlation agree with their counterparts on two very important points:
- Just spending more money does not CAUSE outcomes to improve, and
- Spending money wisely makes the difference, not how much is spent.
This chart shows Kansas’ scores on the National Assessment of Educational Progress (NAEP) have remained relatively unchanged since 1998 even though per-pupil spending has increased significantly and well beyond inflation.
Figure 2 below comes from a 50-state comparison of 2014 per-pupil current operating spending (most recent US Census data) adjusted for cost of living and the 2015 NAEP Index as calculated by Education Week; the red star represents Kansas. It’s obvious that the same or very similar results are achieved at significantly different spending levels and from a statistical standpoint, the R2 value of 0.04 means there is virtually no relationship between spending and outcomes.
Finally, the chart below from State Education Trends published by the Cato Institute shows that achievement for 17-year olds in the U.S. between 1970 and 2012 was essentially unchanged even though inflation-adjusted spending grew quite significantly.