Many decisions involve a trade-off between now and the future. Whenever we invest our time or money, we are giving up something today to obtain something in the future.So by saving some of our income, we give up consumption now for consumption in the future. When we go to a university, we give up income and leisure time today to get more consumption in the future. What principle of economics does the statements depict? Please show steps how you get an answer and please be clear in your explanation.