Ghani’s science translated perfectly into politics. Those fickle shoppers who switched brands to save a few cents, for example, behaved very much like swing voters. In the supermarket, it was possible to estimate how much it would cost to turn each shopper from one brand of ketchup or coffee to another more profitable brand. The supermarket could then pick out, say, the 15 percent most likely to switch and provide them with coupons. Smart targeting was essential. They certainly didn’t want to give coupons to shoppers who were ready to pay full price. That was like burning money.
