Editing United States antitrust law (section)

===Predatory pricing===
{{main|Predatory pricing}}
In theory predatory pricing happens when large companies with huge cash reserves and large lines of [[credit (finance)|credit]] stifle competition by selling their products and services at a loss for a time, to force their smaller competitors out of business. With no competition, they are then free to consolidate control of the industry and charge whatever prices they wish. At this point, there is also little motivation for investing in further [[technology|technological]] research, since there are no competitors left to gain an advantage over. High [[barriers to entry]] such as large upfront investment, notably named [[sunk costs]], requirements in infrastructure and exclusive agreements with distributors, customers, and wholesalers ensure that it will be difficult for any new competitors to enter the market, and that if any do, the trust will have ample advance warning and time in which to either buy the competitor out, or engage in its own research and return to [[predatory pricing]] long enough to force the competitor out of business. Critics argue that the empirical evidence shows that "predatory pricing" does not work in practice and is better defeated by a truly [[free market]] than by antitrust laws (see [[Predatory pricing#Criticism|Criticism of the theory of predatory pricing]]).

*''[[Brooke Group Ltd. v. Brown & Williamson Tobacco Corp.]]'', 509 U.S. 209 (1993) to prove predatory pricing the plaintiff must show that changes in market conditions are adverse to its interests, and that (1) prices are below an appropriate measure of its rival's costs, and (2) the competitor had a reasonable prospect or a "dangerous probability" of recouping its investment in the alleged scheme.
*''[[Weyerhaeuser Company v. Ross-Simmons Hardwood Lumber Company]]'', 549 U.S. 312 (2007) a plaintiff must prove that, to make a claim of predatory buying, the alleged violator is likely to recoup the cost of the alleged predatory activity. This involved the saw mill market.
*''[[Barry Wright Corp. v. ITT Grinnell Corp.]]'' 724 F2d 227 (1983)
*''[[Spirit Airlines, Inc. v. Northwest Airlines, Inc.]]'', 431 F. 3d 917 (2005)
*''[[United States v. E. I. du Pont de Nemours & Co.]]'', 351 U.S. 377 (1956)