Measuring SMO Populations: Methods for Compiling a Comprehensive 100-Year Time-Series of National U.S. Environmental Organizations.

Social movement organizational studies have primarily relied on the analysis of one source. Recently study showed the use of one source was inadequate to study the population of environmental groups at the state level. This raises questions regarding the use of single sources for the study of national and international social movement organizations. A single source that has become a standard for social movement organization research is the Encyclopedia of Associations, however, we know of only one paper assessing the adequacy of the EofA's coverage of movement organizations. Overall, an important component in the analysis of social movements is the adequacy and reliability of the data utilized. We need to know if multiple sources will result in a significant difference from the analyses based on a single source. To accomplish this, we used 155 sources (IRS data, directories, books, reports, proceedings, and web sources) to gather a comprehensive population data set of national and regional U.S. environmental organizations over a 100-year time-series. The purpose of this paper is to describe the methods used in this analysis. Our research and methods revealed that the use of a single source, such as the EofA, is significantly insufficient for studying the U.S. environmental movement population. Multiple sources are needed, including the web and IRS data files, in order to capture a representative population. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]