One study found Walmart's entry into a new market has a profound impact on its competition. When a Walmart opens in a new market, median sales drop 40 percent at similar high-volume stores, 17 percent at supermarkets and 6 percent at drugstores, according to a June 2009 study by researchers at several universities and led by the Tuck School of Business at Dartmouth College.[127] A Loyola University Chicago study suggested that the impact a Walmart store has on a local business is correlated to its distance from that store.