For decades, large businesses have been taking market share from small businesses, and the corporations at the top of the pyramid have been consolidating into ever-bigger megacorporations. In the 1980s, half of retail shopping took place in independent stores; today, it is less than one-quarter. From 2002 to 2017, Home Depot and Lowes almost doubled their joint share of the home-improvement retail market, from 42 to 81 percent. Even before the coronavirus struck, in 43 metropolitan areas more than half of all groceries were bought at Walmart.