Partial deregulation has occurred in a broad range of industries, from telecommunications to transportation to financial services. This first phase of deregulation has given impetus to an intensive debate over future regulatory policy. Some commentators advocate further partial deregulation of industries such as natural gas and electric power while others push for re-regulation of airlines and railroads. The immediate question is whether the deregulation that has taken place will achieve the benefits of market competition or will create instead imperfect markets that are neither fish nor fowl, markets that are less efficient than if they were either fully regulated or fully competitive. The question arises from the inherent nature of partia...