I rarely disagree with Don Boudreaux about any economic, political, or moral issue and so in those rare cases where I do disagree, it’s probably worth noting. Here’s one.

In a post in September, I talked about which U.S. presidents belong on Mount Rushmore. In a comment, Don wrote:

I’d remove from Mt. Rushmore all people who are most famous for holding political office – which is to say, I’d blast off all four of the currently sculpted faces. I’d replace them with images of the faces of John D. Rockefeller, Sr., Gustavus Swift, J.J. Hill (even though he was Canadian!), and either Gail Borden or Steve Jobs – people who really define, and who helped in notable and noticeable ways to sculpt, what is good about America. (If obliged to include a non-entrepreneur among the four, there’s no question that the person whose visage I would choose is that wisest of all Americans, H.L. Mencken.)

I agree with Don about the merits of Rockefeller, Swift, Hill, and Jobs. And I hadn’t known about Gail Borden, but now I do, and I see Don’s point.

But I want to make my case for putting only Presidents on Mt. Rushmore. It’s an application of public goods theory. As David Friedman has pointed out so eloquently (see his “The Right Side of the Public Good Trap” in The Machinery of Freedom), in a society with government, good law is a public good. It is non-excludable: If someone provides good law, even those who don’t pay benefit from it because it is hard to keep them from free-riding. It is non-rival in consumption: my benefiting from good law doesn’t prevent you from doing so.

The fact that good law is a public good means that it will be under provided. There are many incentives for politicians to provide the opposite of good law: they benefit and their cronies benefit. And no one knows this better than Don. Read his great letters to politicians and you’ll see him excoriating politicians for pushing bad laws. That, sigh, is where the incentives typically are.

So when a politician comes along who pushes good laws or vetoes bad ones, that’s a big deal. How do we get better law, on the margin? By praising politicians who push for good laws and excoriating politicians for pushing bad ones. (Don does really well at the latter.) Do I want praise of entrepreneurs too, for the immense good they do for society? Yes, I do. But here’s the neat thing: keep regulations to a minimum and don’t tax them heavily, and the large financial incentives for entrepreneurship will get us lots of entrepreneurs and lots of benefits for society.