A recent study from the National Bureau of Economic Research argues that Wal-Mart's size and lower-than-average prices have pushed the US inflation rate substantially below what official statistics indicate. According to the study's authors, the government's current inflation metric assumes that lower prices at big-box discounters mean products of lower quality, but the authors insist the food products available at Wal-Mart tend to be exactly the same as those at local supermarkets. More details are presented.