Source: http://www.newyorker.com/talk/financial/...

Our main yardstick for the health of the economy is G.D.P. growth, a concept devised in the nineteen-thirties by the economist Simon Kuznets. If it’s rising briskly, we know that the economy is doing well. If not, we know it’s time to worry. The basic assumption is simple: the more stuff we’re producing for sale, the better off we are. In the industrial age, this was a reasonable assumption, but in the digital economy that picture gets a lot fuzzier, since so much of what’s being produced is available free. You may think that Wikipedia, Twitter, Snapchat, Google Maps, and so on are valuable. But, as far as G.D.P. is concerned, they barely exist.