This is hidden brain.
I'm Shankar Vedantam.
There's something about the prospect of getting a good deal that does curious things to our minds.
Imagine, for example, that you need to buy a new bedspread.
You're in luck, because there's a sale happening right now at a store near your house.
Usually, the bedspreads are priced according to size.
A double costs 200, a queen costs 250, and a king size bedspread costs $300.
But on this day, all the bedspreads are on sale.
For the low, low price of $150, you have a double bed.
The question is, what size bedspread do you buy?
The behavioral economist Richard Thaler once told me about a friend who faced just this situation.
She had a double bed.
Again, the usual price was 200.
The sale price was 150.
She was ecstatic about the idea of saving $50.
But then she got to thinking about how she could save even more.
If she bought the queen, she'd save $100.
And if she bought a king size bedspread, she would save a whopping $150.
You can guess where this is headed.
She snapped up the best deal, went home with the king.