TRAINING KEY 114: Nonresponse

Practical Methods for Design and Analysis of Complex Surveys.
Risto Lehtonen and Erkki Pahkinen

TRAINING KEY 114: Nonresponse



INTRODUCTION

A) REFERENCE EXAMPLE 4.1: SAS CODE AND OUTPUT

Evaluation of the bias due to nonresponse in the Province'91 population.

Nonresponse can be harmful in two ways:

  1. Estimation can be biased if the characteristics of the nonrespondents systematically differ from those of the respondets. For example, in the case of a population total T, this difference may cause nonresponse bias defined as , where is a Horvitz-Thompson estimator calculated from the respondent data.
  2. Estimation can be less efficient than planned, because under unit nonresponse, the number of measurements is less than the original sample size (n(r) < n) thus decreasing the denominator of the standard error formula.