Chapter 4 shows that a good part of the decrease in competition has resulted from the recent wave of large mergers. Merger regulation, which is based solely on economic considerations, is limited to assessing the potential anticompetitive effects among the competing firms, without any consideration of the size alone of the combined firm or the effects on noncompeting firms. In addition, many mergers are justified by a claim of increased efficiencies in the new firm, which is often the result of layoffs and plant closures. Not only does this cause significant job losses, it also hurts families and communities. Even though economic theory does not take these kinds of externalities into account, they are nonetheless harmful consequences of mergers. Numerous studies have shown that many mergers do not result in lower prices, while some mergers have even led to price increases. In these mergers, workers suffered not for the sake of consumers but for the financial benefits reaped by the shareholders and managers of the merging firms and by the professionals who put the deals together. It also appears that investment advisors encourage mergers just so that they can profit from the transactions, regardless of the degree of benefit provided to consumers (or even shareholders). With little or no benefit to consumers from some mergers and significant harm to labor, the chapter argues that we need to reassess how the government should review mergers.