you have lent your brother 1000 laris, and because he is a close family
member, you do not charge interest from him. One day you get a phone
call from your brother, and he offers you to pay back the debt either
today or in one year from now. What would you choose? If you act in line
with standard economic theory, you would choose to get the money back
today. You are driven by what economists call time preference, a kind of
“psychological interest rate” with which you discount future payoffs.