Regulated electric utilities historically have undertaken several public purposeprograms in addition to selling electricity. These activities generally relate tothe provision of electricity but have benefits that extend beyond the utility and the customers they serve. They include offering rebates to consumers who purchase energy-efficient appliances, that is, the so-called demand-side management

(DSM) programs; promoting use of renewable fuels; funding industrywide research and development (R&D) of more efficient generating technologies; and subsidizing electricity purchases by low-income households. Some of these activities have been imposed upon the utility by regulatory or legislative mandate, whereas others have been largely voluntary.