Two prominent Canadian authors argue that government at times has to intervene to ensure competition in large and important industries. Naomi Klein illustrates this roughly in her work "The Shock Doctrine" and John Ralston Saul more humorously illustrates this through various examples in "The Collapse of Globalism and the Reinvention of the World". While its supporters argue that only a free market can create healthy competition and therefore more business and reasonable prices, opponents say that a free market in its purest form may result in the opposite. According to Klein and Ralston, the merging of companies into giant corporations or the privatization of government-run industry and national assets often result in monopolies or oligopolies requiring government intervention to force competition and reasonable prices. Another form of market failure is speculation, where transactions are made to profit from short term fluctuation, rather from the intrinsic value of the companies or products. This criticism has been challenged by historians such as Lawrence Reed, who argued that monopolies have historically failed to form even in the absence of antitrust law. This is because monopolies are inherently difficult to maintain as a company that tries to maintain its monopoly by buying out new competitors, for instance, is incentivizing newcomers to enter the market in hope of a buy-out.