A smaller number of companies are coming to dominate the U.S. and other advanced economies, gobbling up market share and making record profits. What's causing it, and how's that affecting you as a consumer, as a worker or as an entrepreneur? Chris Condon examines how market concentration may be eroding competition and the very dynamism of our economy. Plus, Stephanie sits down with Bloomberg Opinion writer Noah Smith to dissect just how worried we should be about this phenomenon, the threat of idea hoarding, and the underrated benefits of exports.