Yeah, I know, that’s not news. In today’s Globe, Jeff Jacoby has a polemic entitled The debate shifts to the left. Here’s his thesis.

A more liberal policy agenda isn’t all that will be moving into the spotlight. There will be a heightened focus on liberal arguments as well — which means we’ll be hearing more about good intentions and less about good results. Political discourse will dwell even more than it already does on “fairness” and “compassion” and “unmet needs” — and even less on factual evidence and the historical record.

Here’s the example he chooses.

The minimum-wage issue illustrates the pattern. Proponents of this quintessentially liberal prescription emphasize the difficulties faced by those trying to make a living and support a family while working a minimum-wage job.

Opponents, by contrast, point to data and economics. They note, for example, that most minimum-wage workers are neither poor nor family breadwinners, but singles in their teens or early 20s, often students working part-time while living with Mom and Dad.

Note that JJ doesn’t provide any sources. Here’s one. (Yes, I know it’s slightly old, but it’s highly doubtful that much has changed.) How do minimum-wage opponents’ claims match up against the actual facts? Well, according to this source and consistent with others, 71% of those under the prevailing minimum wage and 79% of those above that but below the proposed minimum wage (the cutoff that really matters) are in families at 150% of the poverty line or less. They might not be totally destitute, but they are poor, so one half of Jacoby’s claim is patently false. As for breadwinners, he might be technically correct. Between 19.2% and 24.6% of the sample are parents, so some even smaller number must be breadwinners. That’s misleading, though, because in poor families the “breadwinner” often doesn’t earn all of the bread. For example, I worked in high school but all of my income went toward putting food on the table instead of movies and video games like it would for wealthier kids. The composite statement that “most minimum-wage workers are neither poor nor family breadwinners” remains false in any case because most are one or the other even if they’re not both. Similarly, while most minimum-wage workers are students and some work part-time (often not by choice) and some (probably few of the 53.2% to 57.9% over age 25) live with Mom and Dad, to say that “often” minimum-wage workers meet all three criteria is a stretch. Not often enough for that to be anything more than another convenient stereotype. Let’s look at the next misstatement.

“The enactment of the first federal minimum wage law in 1933,” writes economist Thomas Sowell, “raised the average wage rate in the Southern textile industry by 70 percent — and half a million blacks nationwide lost their jobs.”

Hm. How do you reconcile that with this statement from my source?

Overall, recent studies have found that minimum wages have negative effects on employment but the magnitudes have varied across studies. At the lower end, researchers have found that a 10 percent minimum wage hike would reduce employment by only 1 percent. At the high end, other researchers have found that the same hike would reduce employment by 10 percent.(8) Moreover, other studies have concluded that minimum wages have no effect or a positive effect on employment.(9)

Well, we might start to distinguish the two by noting that JJ’s claim is unsubstantiated and comes from a prominent full-time employee of the right-wing noise machine, while mine is thoroughly substantiated and comes from the US government. Which is closer to “relying on data and economics” as JJ seems to think we should?

Jacoby isn’t afraid that “factual evidence and the historical record” will be supplanted by appeals to compassion. He’s afraid that factual evidence and the historical record will be more prevalent, supplanting the myths and distortions he uses to deny any need for compassion. He’s afraid that the debate will become more empirical and rational, not less.