This is Planet Money from NPR.

Welcome back, everyone, to Planet Money Summer School, government edition.

The only economics degree you can get at 1.7 times normal speed.

Very efficient, saves a ton of time.

Today, we boldly go into the arena of competition known as the market. In economics,

a market is a place, even virtual, where buyers and sellers interact to exchange goods or services.

And economists love markets. It's like all of our supply and demand graphs have come to life.

People buying, people selling, shouting out prices. Wherever humans

have congregated, markets have formed. Thousands of years ago, it was trading wheat and shells

and copper. Hundreds of years ago, stock markets formed. Everything you buy goes through some

sort of marketplace. Your cup of coffee came from trading in the bean markets. Your spouse might have come from the dating marketplace on the apps.

Even kids will tell you one Snickers is worth at least two twicks.

It's a law of nature.

But sometimes, as we'll see today, markets can go terribly wrong.

Greed can run out of control.

Lives can be at risk.

That's when the government often steps in.

It gives the market a little nudge to work better. This is class number six, market design.

This is such a cool and interesting area. We wanted not just a professor to help us along,

but a market designer, the invisible hand made visible. My name is Alex Tatelbeum, and I'm a professor

of economics at the University of Oxford in England. I bet in England you don't need to say

the in England part. Not every time. So Alex, as a market designer,

...