Examples of benefits or costs of the current concentration wave are scanty. Yet it is hard to imagine that the merger of a few oil firms today could recreate the same threats to competition that were feared nearly a century ago in the U. S. , when the Standard Oil trust was broken up. The mergers of telecom companies, such as WorldCom, hardly seem to bring higher prices for consumers or a reduction in the pace of technical progress. On the contrary, the price of communications is coming down fast. In cars, too, concentration is increasing—witness Daimler and Chrysler, Renault and Nissan—but it does not appear that consumers are being hurt.