Adjusting undercoverage and nonresponse bias in telephone interviews

This paper investigates the noncoverage bias in CATI-surveys. This bias is introduced by the restriction of using the telephone as a communication medium. Obviously, only that part of the population that disposes of a listed, fixed-line telephone can be interviewed by means of CATI.. Data from a CAPI-survey, the Integrated Survey of Living Conditions, is used to assess the noncoverage bias when restricting the sample to individuals that own a listed, fixed-line telephone.Individuals with and without a listed, fixed-line number are compared. Two methods to adjust for the noncoverage bias are applied to the data from the Integrated Survey of Living Conditions: linear weighting and propensity score stratification. Finally, a strategy is explored to simultaneously adjust for nonresponse and noncoverage bias.