The Interstate Commerce Act and Sherman Antitrust Act were passed within 3 years of each other. Although regulation and antitrust both address market power, the ICA and Sherman Act had different objectives. After a minimal reference to just and reasonable prices, the ICA focused on preventing...

Cost-of-service regulation that reduces prices will also reduce incentives to control cost. Increased output counteracts this trend when there are economies of scale. We derive closed-form approximations for the maximum cost increase that leaves a positive welfare gain when regulation reduces...