The problem is that people basically dangle debt in front of us. And the cost for the poor of course is much higher than for the wealthy.

If you want to spend more money in restaurants, use credit cards more than cash. If you want to spend less, use cash more than credit cards. But in general, we can think about how to use the pain of paying and how much of it do we want. And I think we have like a range. Credit cards have very little pain of paying, debit cards have a little bit more because you feel like today, at least it is coming out of your checking account, and cash has much more.

The problem with opportunity cost is that opportunity cost is divided among many, many things.

individuals are honest only to the extent that suits them (including their desire to please others)

Money are very difficult to think about. So, we think about money as the opportunity cost of money. So, we at some point went to a Toyota dealership and we asked people, what will you not be able to do in the future if you bought this Toyota?

We need to believe that we're good people, and we'll do just about anything to maintain that perception.

In the U.S., I think there is an ideology of not telling kids what to do. Nobody to tell you who to marry, not tell you what job to pick. You're your own person. You have the freedom to choose, including the freedom to fail in magnificent ways. And I think that's the big difference. In other countries there is basically a social norm about saving that is passed from generation to generation. In the U.S. there isn't.