Roughly 140,000 people in the United States (according to the most recent reliable estimate: as long ago as 1994!) call themselves "economists." Compared with the-then 925,000 lawyers and 720,000 doctors this may not seem like much. The number is more impressive, at any rate academically, when one considers that it is eight or ten times the number of sociologists or historians.
Of these 140,000 economists, fewer than half have advanced economics degrees (M.A. and Ph.D). About three-fifth works for banks, consulting firms, and other businesses, about one-fifth work for universities and colleges, and about one seventh work for the Federal and state governments. The remainder work for non-profit institutions and elsewhere. The one-fifth in higher education were in 1994 about 28,000, roughly 3 percent of all teachers of college students. Many non-academic economists do not have jobs with "economist" in the title. Yet their economics enables them to help business and government and non-profits do the world's work.
Pure economists are a recent phenomenon. Adam Smith is remembered as a ethical philosopher and as an economist, but he could just as well be named the inventor of sociology. Marx could be called a philosopher, a sociologist, or a historian. And Keynes's first works were philosophical and mathematical. Nowadays only a few professional economists carry more than one label. Most academic economists operate within departments with "Economics" on the letter head (one-fourth in colleges of business, three-quarters in colleges of arts and sciences). They converse mainly with other academic economists. Economists who win the Nobel Prize in economics---itself a recent event: the first was given in 1969---are usually unknown even to the educated public. They are, as their theory of free trade would advocate, highly specialized in economic science.