Experimental testing of refusal conversion strategies in a large-scale longitudinal study.

Refusal conversion is one of the fieldwork strategies commonly used to minimisenon-response in surveys. However, there is relatively little evidence about theeffectiveness of this strategy, particularly in face-to-face longitudinal surveys.Moreover, much of the existing evidence is based on observational studies. Thispaper evaluates the effectiveness of fieldwork strategies to covert refusals usingevidence from a randomised experiment implemented on a large-scale longitudinalstudy in the UK. We show that intensive re-issuing is an effective way of increasingthe proportion of refusals converted to a productive interview and hence increasingthe sample size and reducing the refusal rate. We also show that refusal conversionmay have led to a reduction in non-response bias in the survey estimates for severalkey variables.