During the 1970s and early 1980s utility regulators moved from largely unintrusive regulatory practices towards more aggressive and intrusive strategies. This study explores the reasons for the change and examines the trade-offs involved between seeking fairness to customers and efficiency of operations as primary goals of regulatory policies. An extended case study of the California Public Utilities Commission's conservation policies and utility programs from 1975 to 1984 is used to test theoretical explanations of interventionism. In a look toward the future of interventionist regulatory...