The main concern of macroeconomics is to understand the overall workings of an economy for the purpose of helping an economy to allocate goods and services in the most efficient way possible and also in a way that will do the most people the most good. In a capitalistic society, this involves studying the supply of goods and services, the demand for goods and services, prices of goods and services, the gross domestic product (GDP), employment and unemployment, and government policy, for example, tax policy, price controls, and controls on supply. All of this is studied in the aggregate, rather than focusing on the actions of individuals. Economists gather data and make models of their data, to ascertain what is and is not working and to project to find out what may or may not work, in the hope of meeting their purpose. Some work for universities, teaching and doing research, some work for government as advisers, some work for industry, some work for consumer groups, and some work independently. Theoretically, all have the same concern, but there is some politicization in economics, which means that the notion of what will do the most people the most good is sometimes arguable among economists.