Despite all the talk of a “war on science” being waged by political conservatives and Republican politicians — to match their supposed wars on women, men, the young, and the old, no doubt — North Carolina now features a shrill and relentless rhetorical war on social science by political liberals and Democratic politicians.

In editorials, sound bites, social media, and floor debate, the Left continues to insist that state and local tax burdens have no effect on economic growth, that higher state spending on Medicaid and unemployment insurance creates jobs, that teacher assistants boost student achievement, and that offering teachers bonuses to obtain graduate degrees makes them more effective in the classroom.

None of these claims has empirical support. For decades now, social scientists have examined each and found them wanting. I’m not referring to the work of scholars at think tanks such as the Cato Institute, the American Enterprise Institute, or the John Locke Foundation, although I obviously think their contributions are valuable. I’m referring to professors of various disciplines and personal views who publish their findings in peer-reviewed journals.

When liberals claim that taxes don’t affect job creation or economic growth, they are ignoring the results of hundreds of academic studies published since 1990 that reveal negative relationships between state economic performance and overall tax burdens (in 63 percent of the relevant studies), property taxes (61 percent), sales taxes (65 percent), business taxes (67 percent), and marginal income tax rates (70 percent).

When liberals claim that higher state spending on public assistance programs boosts the economy — by increasing the purchasing power of recipients for example — they are ignoring the results of 62 academic studies published on the issue since 1990. In two- thirds of them, higher state spending on public assistance was associated with less economic growth, not more.

When liberals complain that Republican proposals to transfer tax dollars from funding teacher assistants to raising teacher pay will do more harm than good, they are ignoring the fact that 69 percent of studies on the subject found the presence of teacher assistants has no measurable effect on student learning, while the vast majority of empirical research finds the quality of classroom teachers to be a key factor.

And when liberals complain that ending bonuses for graduate degrees will harm teacher quality, they are ignoring a veritable mountain of evidence — 81 percent of the 114 studies published since 1990 — that teachers with graduate degrees are no more effective than teachers without them. It turns out that teacher quality is best evaluated directly on the basis of principal evaluations, value-added test scores, or both, not indirectly on the basis of credentials or years of experience.

By no means do I mean to suggest that every important question about state fiscal and education policy has been answered. Social scientists and policy analysts will have plenty to research, study, and argue about for decades to come.

But some propositions about public policy have now been established beyond a reasonable doubt. For liberals to insist that North Carolina’s recent decisions to reduce and reform taxes, limit entitlement spending, and redirect education dollars to performance-based teacher compensation are “mean-spirited,” “extreme,” “ideologically motivated,” or “immoral” is to establish only that they are ignorant of or indifferent to the findings of modern social science.

It is as if they are flimflammers at a medicine show, holding up colorful bottles of flavored water and promising to cure arthritis, influenza, impotence, and cancer. When challenged to support their claims, they cite folk wisdom and unverifiable anecdotes.

Now, con men got away with old-time medicine scams either by moving from town to town, making money on one-time sales and then fleeing before their rackets were exposed, or by putting liquor in the bottles to provide sufferers with temporary feelings of relief rather than true cures.

Here’s the difference: I believe that many if not most critics of North Carolina’s new fiscal and economic policies actually believe their own sales pitches. They aren’t fly-by-night scam artists. They actually consume their own wares.

How sad.

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Hood is president of the John Locke Foundation.