To assist the National Endowment for the Arts (NEA) in making decisions about the Endowment's future role in the development of new, and improvement of existing, economic data on the arts and cultural institutions, all the existing sources of economic data on the arts were examined and evaluated in detail. A needs survey was also conducted. A sample of arts councils and arts-producing organizations was approached by a mail inquiry and people concerned with the arts were interviewed to find out which existing sources they found helpful. The report begins by describing the characteristics of the data sources examined. Sources included standard federal statistical series, unpublished data on arts organizations in the files of the NEA, the Internal Revenue Service, the New York State Council of the Arts, data collected by various service organizations, proprietary data on the commercial theater, and major one-time and irregularly recurring surveys. The expressed needs of users of the data, as found in the survey, are discussed; the costs of producing the existing data are examined; and a summary of the cost-effectiveness rankings of the better data sources is presented. Recommendations for data improvements are made. (RM)