TY  - JOUR
AU  - Abraham,Katharine G.
AU  - Helms,Sara E.
AU  - Presser,Stanley
TI  - How Social Processes Distort Measurement: The Impact of Survey Nonresponse on Estimates of Volunteer Work
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 14076
PY  - 2008
Y2  - June 2008
UR  - http://www.nber.org/papers/w14076
L1  - http://www.nber.org/papers/w14076.pdf
N1  - Author contact info:
Katharine G. Abraham
Joint Program in Survey Methodology
1218 LeFrak Hall
University of Maryland
College Park, MD  20742
Tel: 301/405-1004
Fax: 301/314-7912
E-Mail: kabraham@survey.umd.edu

Sara E. Helms
Department of Finance
Economics and Quantitative Methods
BEC 317-F
University of Alabama at Birmingham
1530 3rd Ave South
Birmingham, AL 35294
E-Mail: shelms@uab.edu

Stanley Presser
Department of Sociology and Joint Program in
  Survey Methodology
1218 LeFrak Hall
Joint Program in Survey Methodology
College Park, MD  20742
E-Mail: spresser@socy.umd.edu
AB  - Estimates of volunteering in the United States vary greatly from survey to survey and do not show the decline over time common to other measures of social capital.  We argue that these anomalies are caused by the social processes that determine survey participation, in particular the propensity of people who do volunteer work to respond to surveys at higher rates than those who do not do volunteer work.  Thus surveys with lower responses rates will usually have higher proportions of volunteers, and the decline in response rates over time likely has led to increasing overrepresentation of volunteers.  We analyze data from the American Time Use Survey (ATUS) -- the sample for which is drawn from Current Population Survey (CPS) respondents -- together with data from the CPS Volunteering Supplement to demonstrate the effects of survey nonresponse on estimates of volunteering activity and its correlates.  CPS respondents who become ATUS respondents report much more volunteering in the CPS than those who become ATUS nonrespondents.  This difference is replicated within demographic and other subgroups.  Consequently, conventional statistical adjustments for nonresponse cannot correct the resulting bias.  Although nonresponse leads to estimates of volunteer activity that are too high, it generally does not affect inferences about the characteristics associated with volunteer activity.  We discuss the implications of these findings for the study of other phenomena.
ER  -