The U.S. Federal Trade Commission will launch an investigation of the business practices of so-called patent trolls in an effort to understand whether those companies are harming competition and consumers, the agency's chairwoman said. As part of a growing focus of the U.S. government on patent abuses, the FTC will study patent assertion entities (PAEs), companies with the primary business model of buying and licensing patents, in an effort to understand the costs and benefits of PAE activity, FTC Chairwoman Edith Ramirez said Thursday.