1. Do declining response rates negatively affect sample composition
Do declining response rates negatively affect sample composition? A longitudinal analysis using data from the German General Social Survey (ALLBUS)
Michael Blohm und Achim Koch, GESIS – Leibniz Institute for the Social Sciences
June 27, 2018
Session number: ST 7

2. Starting point
Declining response rates are a continuing problem for household surveys - with voluntary participation - in many Western countries
The decrease in the response rate raised concerns whether it would be accompanied by an increase in nonresponse bias.
German General Social Survey (ALLBUS) provides a good opportunity to analyze the relationship between declining response rates and nonresponse bias
same basic survey design since 1994
accurate calculation of response rates

3. German General Social Survey (ALLBUS)
Multi-topic survey
Repeated cross-sections (every 2 years)
Face-to-face
Sample of named individuals
Population: 18yrs and older in private HH (in Germany)
Commercial survey agency
3500 net cases
70 min.

4. Indicators for Nonresponse Bias
R-Indicators: Variability of estimated response propensities 𝑹=𝟏−𝟐𝑺(𝒑)
Logistic regression models: DV Survey Participation IVs: Gender, Age, Nationality, Urbanicity, Region
Gross sample: Frame information from population registers
Conditional partial R-Indicators: measure the relative importance of a variable on the variability
Index of Dissimilarity: Deviations from the German Microcensus (external benchmark)
Comparison for Gender, Age, Education, Marital Status, Work Status, Occupational Status, Household size
Net sample

5. Results: R-indicator

6. Results: Index of Dissimilarity

7. Summary/Discussion
Despite a decrease in the response rate of 20 %points:
better balanced sample composition (sample frame information and the respective R-indicator)
equally well balanced sample (external benchmark data and the average value of D)
smaller nonresponse bias for most variables
increase in nonresponse bias for some variables
== > response rates alone are an imperfect indicator of nonresponse bias

8. Thank you for your attention
Do declining response rates negatively affect sample composition? A longitudinal analysis using data from the German General Social Survey (ALLBUS)
Thank you for your attention
Michael Blohm und Achim Koch, GESIS – Leibniz Institute for the Social Sciences