Planet Money did an episode on that quite recently: http://www.npr.org/sections/money/2017/01/27/512060753/episode-750-retraining-day http://www.npr.org/section

Planet Money did an episode on that quite recently: http://www.npr.org/sections/money/2017/01/27/512060753/episode-750-retraining-day http://www.npr.org/sections/money/2017/01/27/512060753/episo...