The danger of assholes like Caplan is he can bloviate a bilious bag of bullshit and what you say is "the conventional wisdom" is "one theory." This is the principle problem with economics: any given asshole, with the proper backing, can come up with the idea that "monopolies are good" and a whole bunch of chin-stroking American Enterprise Institute troglodytes will throw eighty eight gajillion dollars at propagating the idea that we haven't beaten this shit into the ground and before too long, here's fucking Ben Shapiro, knowing beyond a reasonable doubt that monopolies are good before he knows beyond a reasonable doubt that soiling his diaper is bad.

I mean, fuckin' hell, dude.

Tenet #1: The main reason today’s workers have a decent standard of living is that government passed a bunch of laws protecting them.

Google image search: standard of living vs productivity

HOLY FUCKING SHIT IT'S AS IF THERE WAS A MASSIVE DECORRELATION THAT PERFECTLY MATCHES CONSERVATIVE ECONOMIC THEORY

and you can do this with every single point he makes. Every. Single. Thing. he has to say can be completely discounted and discredited with the barest minimum of effort. It's a fucking house of cards and the really pernicious thing about this shit? You're smart enough to know that. You're smart enough to google this shit yourself. But you don't because there's some smarmy authority figure puckishly arguing that Upton Sinclair was overreacting.

Why do large group differences exist?

Because "work" is a cultural construct and cultures differ. We're just now getting around to the idea that housework is work, despite the fact that we used to sell amphetamines so that women could get through their fucking day. See, this is my problem: this shit is easy but because it's postured as if it's hard you're left agog wondering who said the sky was blue in the first place.