A new report published by two conservative think tanks argues the cognitive ability of teachers is on average lower than private sector workers with similar education backgrounds.

Co-released by the Heritage Foundation and American Enterprise Institute, the authors of the study sought to demonstrate teachers are not underpaid, contrary to popular refrain, and when factoring in health and retirement benefits, earn 52 percent more than “fair market levels.”

Many progressive voices in the teacher-pay debate show the obverse to be true. The Economic Policy Institute publishes an ongoing policy brief on the gap in wages between public-school teachers and better-paid private-sector workers with similar college degrees. Since 1996, that difference, or “wage penalty,” has increased from a 4.3 percent difference to 12 percent last year. Among men, the wage disparity increased from 15 percent to 23 percent in the same period.

Researchers for the same organization wrote (PDF) in September 2010 that public-employee compensation in general lags behind the private sector, to the tune of nearly $23,000 for bachelor’s holders and $33,600 for those with a master’s.

But the authors of the AEI-Heritage Foundation report eschew the whole idea of education experience forecasting a worker’s earning potential.

“Public-school teachers earn less in wages on aver­age than non-teachers with the same level of education,” the authors write, “but teacher skills generally lag behind those of other workers with similar ‘paper’ qualifications.”

Jason Richwine, co-author of the 26-page report who holds a doctorate in public policy, spoke to The American Independent about the paper.

“The cognitive ability [portion] is just one part in trying to explain why traditional measures, like education, are not adequate to capture teacher skill,” he said.

The authors point to research spanning 50 years indicating degrees in education are easier to obtain with high marks. They include a recent study by economist Corey Koedel in which he examined grade-point averages of graduates at three large research institutions, and found education majors finished with an average GPA of 3.65, while math, science and economics majors graduated with a 2.88.

Meanwhile, the researchers also looked into a robust data set dating back to 1979 called the National Longitudinal Survey of Youth that surveys the same 9,964 men and women biennially on questions relating to education, wages, health and other characteristics. Relying on a military-designed cognitive exam called Armed Forces Qualification Test (AFQT), the authors of the report concluded teacher scores lagged behind private-sector professionals with similar academic backgrounds.

The authors did, however, note teacher pay lines up with an equally educated private-sector employee when cognitive scores are similar.

“The takeaway is that we should not trust just years of education,“ Richwine told TAI. He also cautioned his analysis included all teachers, including gym, art and music instructors, who may sag the cognitive scores of subject-oriented teachers in math and science.

Federal education law under No Child Left Behind has stricter knowledge requirements for educators teaching core subjects.

Sara Mead, an education policy analyst with Bellwether Education Partners, told TAI, “using IQ tests is less common than looking at college entrance exams.” She did say current teachers are, however, “disproportionately drawn from the lower end of the spectrum relative to their peers who pursued a different career path” when comparing SAT and ACT scores.

But a 2004 report from the National Council on Teacher Quality indicates (PDF) soft attributes, like motivating and energy, are the most telling characteristics of how prepared a teacher is for the profession, while SAT scores “account for only a small portion of why some teachers are more effective than others.”

Still, Mead says whether teachers are underpaid or overpaid is a “silly conversation in the sense that there’s a huge variation in teacher pay geographically.”

She added, “If you make generalizations, you’ll be wrong about something.”

Voicing that criticism, during a presentation of the paper’s findings that included its authors at AEI yesterday, guest panelist and economist Robert Costrell, of the University of Arkansas department of education reform, said, “I’m not so wild about this over-under payment exercise.”

The country’s largest teacher unions objected to the report findings. The American Federation of Teachers statement read, in part, “[this study is] the reason many Americans pay no heed to what goes on in Washington, D.C. The AEI report concludes that America’s public school teachers are overpaid—something that defies common sense—and uses misleading statistics and questionable research to make its case.

“Rather than rehashing AEI’s previous anti-public worker reports, let’s spend time heeding the lessons of top-performing nations, which invest heavily in recruiting, developing, supporting and compensating teachers.”

And Kim Anderson, director of advocacy for the National Education Association, said in an email, “not only should we question the reliability of this study, but we should also consider the source.

“The study is funded by the very same groups that are trying to eliminate the right of workers to have a voice in their workplace all together.”

During the media event at AEI, the authors of the report pointed out their methodology attempted to account for summer vacation and the higher job security teachers enjoy during non-recession years, something they called a “separate benefit value.”

They also explained the Bureau of Labor Statistics omits public-sector retirement health plans in its calculations for total teacher compensation, a benefit many public-sector workers receive. Conversely, the authors noted only 18 percent of private-sector workers have employers who foot that bill.