This is the Cato Daily Podcast for Wednesday, April 28th, 2021.

I'm Caleb Brown.

Imagine a world where common defense is provided voluntarily,

though it's not been perfect and the potential costs of getting it wrong are quite large,

Ukraine has tried something like that.

Garrett Wood researches the economics of defense, He argues that in the case of Ukraine

crowdfunding its defense, there are many possible lessons. We spoke earlier this

month. Before we started recording you were describing some of the changes that were made in the

structure of defense in Ukraine and I thought this sounds like a Robert Heinlein novel, the idea that there could be, in a sense, a charitable way to provide for a common defense.

But what are some of the problems that we face in general

when we think about providing a defense for a geographic area?

You know, the first and most obvious is probably the free writer problem that we were discussing, right?

So again, that matters what kind of scale you're looking at.

If we were talking about that ballistic missile defense, it's very easy for a

particular citizen in a country that is being shielded from a ballistic missile

attack to Freewide on the provision of interceptor missiles. It's a lot harder to free ride when you change the scale of defense.

You know, so that example again, you know, if we're neighbors and there's a gang of thieves and they are robbing you and robbing me.

Well if I defend my home it does not provide much of an externality to you.

Am I provided negative externality?

It could.

Because they just say, hey guys, this guy's protected. Let's go hit this other guy's house. Yeah, they might all roll over to your house and it might be a bit of a problem for you

But that's the that's the issue when we're talking about the externalities created by defense you really have to keep the

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