From APM, American Public Media, and WNYC.

This is Freakonomics Radio on Marketplace.

Here's the host of Marketplace, S. Biglin.

It's Freakonomics Time.

Every couple of weeks we're talking with Stephen Dubner,

co-author of the books and the blog about the hidden side of everything

that talked to you against Steven.

Hey you two, Tess, and happy summer Olympics to you.

Happy summer Olympics to you as well.

Thank you.

Thank you.

Looking forward to it, any favorite events for you?

Oh, you know, synchronized swimming, of course.

Oh, I see.

I don't, however, want to talk about gold medals.

I actually want to talk about real gold, okay?

The big economic boost that a host city like London is supposed to get, okay?

But Tess, I'm here to tell you that, well, you can probably guess where I'm going with this, can't you, Tess?

No gold in them, they're hills.

Let's bring in the economists, okay, to throw a little cold water on everything.

Alan Sanderson at the University of Chicago has looked at previous host cities

and he measured their economic gains against what he called twin cities, okay?

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