The Mackinac Center for Public Policy has just released a study I conducted for them on the relationship between school district size and spending. But a funny thing happened on the way to the findings – I discovered something vastly more intriguing than what I set out to investigate.

When trying to statistically isolate the effects of district size on per-pupil spending, you have to control for other factors that might affect expenditures. One thing that economists like to control for is the public’s demand for educational services. If local residents expect more (or less), then district officials may choose to spend more (or less) to meet their demands. This is the traditional “selfless public servant” view of bureaucratic behavior.

But there is an alternative theory of bureaucratic behavior, called “public choice.” Public choice theory says that everyone, including bureaucrats, voters, and elected public officials, is motivated significantly by self-interest. We try to do what is best for ourselves and our families. According to this view, public officials generally endeavor to spend as much as they can, because that is the route to professional growth in the public sector.

As a “Pepsi Challenge” of economic theory, I included control variables for both views of bureaucratic behavior in my model. The result? Public choice theory explains about 15 times as much of the variation in spending between districts as does the selfless public official theory. In other words, public school districts spend as much as they can, regardless of local public demand for their services.

That means the incentive structure of our state-run school monopolies is broken. It encourages profligacy. Is it any wonder that real public school per pupil spending has doubled in the past 30 odd years, without any commensurate improvement in the skills of high-school seniors?

State legislatures wanting to rein in spending thus have only one real hope: introduce new incentives for educators to maximize quality while controlling costs. How do you do that? Competition, parental choice, private ownership of schools, deregulation, and, as much as possible, direct parental funding of schools. The same market structure that has driven rising quality and efficiency in almost every other field for centuries. Throw in a good education tax credit policy and you’ve got universal access to a free education marketplace.