Rival Unionism and Membership Growth in the United States, 1897-2005 (ICPSR 27281)

Published: May 20, 2010

Principal Investigator(s):
Caleb Southworth, University of Oregon; Judith Stepan-Norris, University of California-Irvine


Version V1

This study utilizes time-series data from 1897-2005 to explore the positive and negative effects of rivalry between labor unions. Utilizing econometric factors, it also investigates how competition from rival union federations and independent unions affects union density. Variables include counts of pro-labor and pro-management unfair labor practice cases adjudicated by the National Labor Relations Board, competitor union membership ratio and number ratio, the annual percentage change in union density, and the percentage change in the density of AFL/AFL-CIO membership. Other variables include the percentage of United States House members who belong to the Democratic Party, the percentage of popular votes in presidential elections that favored Socialist or Communist parties, core employment and unemployment, the consumer price index (CPI), and the labor union historical periods: Western Labor Union (WLU), Industrial Workers of the World (IWW), Trade Union Unity League (TUUL), Congress of Industrial Organizations (CIO), American Federation of Labor and Congress of Industrial Organizations (AFL-CIO), and Change to Win (CTW).

Southworth, Caleb, and Stepan-Norris, Judith. Rival Unionism and Membership Growth in the United States, 1897-2005. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2010-05-20. https://doi.org/10.3886/ICPSR27281.v1

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National Science Foundation (SES-0946738, SES-0720282)

University of Oregon. College of Arts and Sciences

University of California-Irvine. Center for the Study of Democracy


1897 -- 2005

2006 -- 2008

Please see the "Rival Unionism and Membership Growth in the United States, 1900-2005" journal article in the ICPSR codebook for more variable and study information.

historical manuscripts

aggregate data

census/enumeration data



2010-05-20 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Checked for undocumented or out-of-range codes.


  • Data in this collection are available only to users at ICPSR member institutions.

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