“…As a result, many internet studies were conducted using data from books. For example, Clay, Krishnan, and Wolff (2001) find that competition leads to lower prices and lower price dispersion, and that widely advertised items have lower prices. Clay, Krishnan, Wolff, and Fernandes (2002) find that even though the average prices are similar between online and physical stores, price dispersion is greater for the former, indicating that online firms do not charge the same prices.…”