This report presents the results of a study of the amount of photocopying of library materials by library staff in United States libraries. A national survey was conducted from a sample of public, academic, special, and federal libraries to determine the annual volume of photocopying undertaken for interlibrary loans, local users, and intrasystem loans. Since interpretations of the Law concerning eligibility for royalty payment appear to vary, data are also given for the amount of photocopying that occurs under various hypothetical conditions of eligibility as they might be interpreted in the new Copyright Law and in guidelines set forth by the National Commission on New Technological Uses of Copyrighted Works (CONTU) for photocopying for interlibrary loans. The report documents the effects of these hypothetical conditions from the perspective of both libraries and publishers. In addition, the report describes alternative royalty payment mechanisms and discusses some advantages and disadvantages of each from the standpoints of small and large libraries and small and large publishers. A summary of the report presents estimates of total volume of photocopying, analyzes implications of the new law from the perspectives of libraries and publishers, and describes alternative payment mechanisms. (Author)