ABSTRACT
Five papers have studied the U.S. Portland cement industry (McBride, 1983; Koller and Weiss, 1989; Allen, 1993; Rosenbaum, 1994; Jans and Rosenbaum, 1997). All fi ve report a positive, statistically signifi cant relation between seller concentration and cement price.1 Koller and Weiss conclude (p. 36), “Cement offers cleaner evidence of the effects of concentration on price than most industries because of its many geographic markets, its standardized product, and its data on fi rm market share and price, none of which depend on the census. We feel the evidence gives strong support to the concentration-price hypothesis.”
