BIAS IN LIST-ASSISTED TELEPHONE SAMPLES

A number of researchers have suggested list-assisted samplingfor the selection of telephone households to overcome some ofthe operational difficulties associated with the Mitofsky-Waksbergmethods of random digit dialing (RDD). An advantage of a list-assistedmethod of RDD is that an equal probability systematic sampleof telephone numbers can be selected and the variances of estimatesfrom such a sample are usually lower than from a clustered designlike the Mitofsky-Waksberg method. The main disadvantage ofthe list-assisted method is that it excludes some householdsfrom the sample, thus creating a coverage bias in the estimates.This article describes research on the coverage bias for a particularmethod of list-assisted sampling. The two key determinants ofcoverage bias are the proportion of households that are noteligible for the sample and the differences in the characteristicsof the covered and not covered populations. The results showthat about 4 percent of all households are excluded in nationalsamples using this method of sampling. Furthermore, they showthat the differences between the covered and uncovered populationsare generally not large. The coverage bias resulting from theseconditions may often be small.     

In Conversation with the American Sociological Association President: Randall Collins on Emotions, Violence, and Interactionist Sociology

Randall Collins est professeur de sociologie à l'University of Pennsylvania et Président de l' American Sociological Association . Dans cette entrevue, R. Collins parle de la sociologie des émotions, de la tradition interactionniste ainsi que de la violence. L'entrevue permet de situer les contributions de Collins dans le développement contemporain de la sociologie critique et la microsociologie interactionniste.
Randall Collins is Professor of Sociology at the University of Pennsylvania and is the President of the American Sociological Association. In the following interview, Collins discusses the sociology of emotions, the interactionist tradition, and violence. The discussion situates Collins' contributions as part of an intellectual trajectory that incorporates elements of critical sociology and the micro-sociology of interaction.     

RELIABILITY OF STATED PREFERENCES FOR CHOLERA AND TYPHOID VACCINES WITH TIME TO THINK IN HUE,VIETNAM

We examine the effect of giving respondents time to think about their stated choices (SC) in a survey of cholera and typhoid vaccine preferences in Hue, Vietnam. Because neither vaccine is widely available in Vietnam, we used the SC approach (a stated preference technique) and gave half of our respondents overnight to think about their choices to make the hypothetical valuation scenario as similar to a real‐life choice situation as possible. Respondents who were given extra time made fewer choices that violated internal validity tests of utility theory, and had lower average willingness to pay (WTP), confirming a result found in similar studies in the contingent valuation literature. (JEL D12, I18, C25)