-
Any purchase is one for the future. If you buy a refrigerator, you are making a commitment to the future so that you have food to eat for the next ten years.
-
The major driver of economics is the equilibrium approach, which has taken various forms over the years. General equilibrium is the statement that all the different parts of the economy influence each other, even if it's remote, like mortgage-backed securities and their demands on automobiles.
-
Decision theory, as it has grown up in recent years, is a formalization of the problems involved in making optimal choices. In a certain sense - a very abstract sense, to be sure - it incorporates among others operations research, theoretical economics, and wide areas of statistics, among others.