In other words the opportunity cost of something must reflect the sacrifice of all things that are given up to get it. If several things with different units of measurement are sacrificed then there can be an adding up problem. Economists recommend overcoming this adding up problem by measuring opportunity costs in terms of the values of what is sacrificed. We will encounter this adding up problem and economists solution to it in the following section of this tutorial. We suggested earlier that it is possible to construct an opportunity set for the economy as a whole.
Consumer goods consist of such things as food, movies, bus fare, haircuts, etc.
Consumer goods are used up in the course of daily living. Capital goods consist of buildings, blast furnaces, tractors, computers, etc. To be more complete in our definition of capital goods we might also include the production of capital that is embodied in humans through formal education and other kinds of training. We might also include the capital that is supplied to us by nature in the form of fossil fuels, minerals, soil, forests, etc. Just as in the movies and beer example we could graph the different mixes of consumer and capital goods that could be produced using all of the labour and existing capital currently available in the economy.