A new look at the determinants of nonnumeric response to desired family size: the case of Costa Rica

Abstract

High levels of nonresponse or inappropriate response to items are a persistent concern in survey research because those who do not answer may not be representative of the study population. Thus nonresponse introduces potential bias in the point estimates as well as in multivariate analyses, which use the responses in question as either an independent or a dependent variable. Researchers often have little recourse but to form a “don’t know” or “not available” category from the failure to respond (or to be responsive). They must either omit these cases, treat them as a separate category, or impute a value on the basis of other characteristics of the respondent (Croft 1991; Kalton and Kasprzyk 1986).

The characteristics of those in the “don’t know” category are rarely analyzed (in relation to those responding), and the content of the inappropriate responses is seldom examined. Questions on desired family size (DFS) and family planning surveys are somewhat of an exception to this pattern, however. The questions generally take the form used in the Demographic and Health Surveys (DHS): “If you could go back to the time you did not have any children and could choose exactly the number of children to have in your whole life, how many would that be?” (Westoff 1991).

Nonresponse to DFS questions is of special interest because childbearing preferences figure prominently in fertility and family planning research. DFS helps to explain present trends in fertility behavior and to predict what may happen in years to come. Moreover, it is used widely to measure unmet needs for family planning services and unwanted fertility, and to project future fertility in cohorts that have not completed their childbearing years.