In late March, Gov. Bev Perdue embarked on a two-week campaign to promote a plan that would fund additional education spending by increasing the state sales tax. Perdue’s statewide solicitation is just the start. Calls for significant increases in the public school budget will grow louder in coming months and reach a fever pitch when the N.C. General Assembly reconvenes in May.

Public school enthusiasts like Perdue do North Carolinians a disservice by focusing on education spending alone. Education expenditures and other inputs are only important insofar as they help communities achieve desirable and measurable outcomes.

That said, a large body of research indicates that the relationship between school spending and student performance is weak. Decades of significant funding increases for our traditional public schools have failed to spur commensurate gains in academic achievement.

Over the past four decades, real per-pupil spending in the United States almost tripled, and, as a result, the U.S. now occupies one of the top spots on international rankings of student expenditures. The story is similar in North Carolina. Since 1970, real per-pupil spending in the state more than doubled. According to the latest international data available, North Carolina’s elementary and secondary schools would boast the sixth and fifth highest per-pupil expenditure in the world, respectively.

Yet, per-pupil expenditure statistics provide little information about the relative quality and productivity of public schools. The nation’s performance on international tests remains average at best. Similarly, studies linking North Carolina’s National Assessment of Educational Progress results to international test scores reveal that the state hovers around the international average in reading and math.

Despite skyrocketing budgets and mediocre outcomes, calls for throwing even more money at public schools resonate with voters. In the most recent Phi Delta Kappa/Gallup Poll, 44 percent of respondents identified funding as the biggest problem for the public schools in their community. Why does the myth of the penniless school survive, even thrive, in the public mind?

A 2011 survey conducted by Education Next and Harvard University’s Program on Education Policy and Governance found that beliefs about funding rely heavily on information and perception. To examine this in greater detail, researchers randomly assigned respondents to two groups — one informed of school district spending and one not provided that information.

Nationally, 59 percent of those who lacked information on spending believed that public schools needed additional resources. On the other hand, only 46 percent of those informed of their district’s spending level thought that public schools should receive more funding. Among parents, the gap was wider. Support for increasing education spending was 73 percent for the uninformed group and 56 percent for the informed group. In other words, many citizens believe schools are underfunded but do not have a factual basis for that belief.

In addition, relatively few respondents were willing to accept higher taxes to pay for education spending increases. A majority of respondents from each group thought that taxes should stay at current levels. Overall, only 28 percent said that local or municipal taxes, which are the primary funding sources for most U.S. public school districts, should increase.

A February 2012 Civitas Institute poll had similar results. Their survey of registered voters in North Carolina found that nearly seven of 10 respondents opposed increasing the state sales tax to boost funding for education. Opposition to the idea was consistent across all demographic characteristics and political ideologies.

The bottom line is that North Carolinians need to become better informed about education and taxes. That’s why we’re here.

Dr. Terry Stoops is director of education research at the John Locke Foundation.