Dishonesty is all about the small acts we can take and then think, 'No, this not real cheating.' So if you think that the main mechanism is rationalization, then what you come up with, and that's what we find, is that we're basically trying to balance feeling good about ourselves.

People are irrational - and predictably so.

None of us always make the best financial decisions.

Money is all about opportunity cost. Every time you spend on something, that's something you can't spend on something else.

Imagine you have six loans, small to huge. People want to close loans and because of that, they try to pay off the small loans, but that's not the right strategy. The right strategy, of course, is to pay the loan with the highest interest rate. People make this mistake and it costs them lots and lots of money, it's a very expensive mistake because interest rates accumulate and become very, very expensive very quickly.

What you should do is wait until the end of each month, and then say, "OK, how much money do I have? How much do I need? Let me send the rest to retirement."

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.