Years ago, The Economist had an interesting article on opportunity cost. At the time, PSY’s Gangnam Style video was a viral hit and was watched more than 2 million times on YouTube. It is 4 minutes and 12 seconds long, which means that 140 million hours, the equivalent of 16 000 years, were spent watching it. With those man-hours, we could have built 4 new great pyramids of Giza!

Travel back in time and watch it again!