Trends in Voluntary Group Membership: Comments on Baumgartner and Walker

This paper examines the contentions of Baumgartner and Walker that membership in voluntary groups has been growing over the last 30-some years and that inadequacies in the standard group membership question mask the growth in recent years. Contrary to their findings, no reliable evidence of secular growth in group membership is found, and the idea that the Standard Question has failed to measure such a trend is refuted. Methodological strengths and weakness of the Standard Question and the 1985 National Election Study (NES) pilot question are also examined. Both are found to be useful if imperfect measures.