Oliver Lipps

Effects of Interviewer Experience on Components of Nonresponse in the European Social Survey

The authors analyze interviewer-related nonresponse differences in face-to-face surveys, distinguishing three types of interviewers: those who have previous experience with the same high standard cross-sectional survey (‘‘experienced’’), those who were chosen by the survey agency to complete refusal conversions (‘‘seniors’’), and usual interviewers. The nonresponse components are obtaining household contact, target person contact, and target person cooperation. In addition, the authors consider whether interviewer homogeneity with respect to these components is different across the three interviewer groups. Data come from the European Social Survey (ESS) contact forms from four countries that participated in the rounds of 2002, 2004, and 2006 and used the same survey agency that, in turn, used the same interviewers to some extent. To analyze interviewer effects, the authors use discrete two-level models. The authors find some evidence of better performance by both senior and experienced interviewers and indications of greater homogeneity for nonresponse components, especially for those with room for improvement. Surprisingly, the senior interviewers do not outperform the experienced ones. The authors conclude that survey agencies should make more efforts to decrease the comparatively high interviewer turnover.

A Note on Improving Contact Times in Panel Surveys

With increasing costs for conducting surveys, many survey agencies resort to implementing call strategies. Obtaining contact in panel surveys as early as possible, without annoying people by contacting them at undesired times and ultimately causing them to refuse, requires using efficient call time strategies. In this research, the author uses call data from the Swiss Household Panel (SHP), a centralized Computer Assisted Telephone Interview (CATI) survey with a randomized (experimental) call-household assignment. Using random effects models, the author analyzes the efficiency gains of obtaining initial contact by assigning optimal times to first calls, and times and spacing to second and later calls depending on household sociodemography and prior call patterns. The author concludes with some recommendations for making early and successful contact during fieldwork.

How to survey displaced workers in switzerland : ways of addressing sources of bias

Studying career outcomes after job loss is challenging because individually displaced worker form a self-selected group. Indeed, the same factors causing the workers to lose their jobs, such as lack of motivation, may also reduce their re-employment prospects. Using data from plant closures where all workers were displaced irrespective of their individual characteristics offers a way around this selection bias. There is no systematic data collection on workers displaced by plant closure in Switzerland. Accordingly, we conducted our own survey on 1200 manufacturing workers who had lost their job 2 years earlier. The analysis of observational data gives rise to a set of methodological challenges, in particular nonresponse bias. Our survey addressed this issue by mixing data collection modes and repeating contact attempts. In addition, we combined the survey data with data from the public unemployment register to examine the extent of nonresponse bias. Our analysis suggests that some of our adjustments helped to reduce bias. Repeated contact attempts increased the response rate, but did not reduce nonresponse bias. In contrast, using telephone interviews in addition to paper questionnaires helped to substantially improve the participation of typically underrepresented subgroups. However, the survey respondents still differ from nonrespondents in terms of age, education and occupation. Interestingly, these differences have no significant impact on the substantial conclusion about displaced workers’ re-employment prospects.

Change of individual BMI in Switzerland and the USA: a multilevel model for growth

ObjectiveThe aim is to analyze and compare individual body mass index (BMI) growth patterns of adults from Switzerland and the US.MethodsThe analyses are based on data from two population representative longitudinal household surveys, one from Switzerland, the other from the US. Each data set contains up to four data points for each adult individual. We use multilevel models for growth.ResultsIt can be shown that growth patterns are different in different cohorts in the two countries: there are only small growth differences in the youngest and oldest, but large differences in the middle ages. The individual BMI increase of the middle-aged Swiss amounts to only half of that in the comparable US individuals.ConclusionGiven the much higher BMI level, especially in the youngest cohort, this points to severe obesity problems in the US middle-aged population in the near future. A positive correlation between individual BMI level and growth may emphasize this fact.RésuméObjectifLe but est d’analyser et de comparer des profils de croissance de l’IMC des adultes au niveau individuel en Suisse et aux USA.MéthodesLes analyses se basent sur les données de deux enquêtes longitudinales représentatives au niveau des ménages, l’une réalisée en Suisse et l’autre aux USA. Chaque jeu de données contient jusqu’à quatre mesures de l’IMC pour chaque individu adulte. Un modèle multiniveau de croissance est utilisé.RésultatsLes résultats montrent que les modèles de croissance de l’IMC sont différents dans les différentes cohortes entre les deux pays: il y a seulement une petite différence de croissance dans les cohortes les plus jeunes et les plus âgées, par contre il y a des différences importantes dans les âges moyens. L’accroissement de l’IMC à l’âge moyen en Suisse s’élève seulement à la moitié de celui aux USA à âge comparable.ConclusionEtant donné le niveau d’IMC nettement plus élevé aux USA, particulièrement dans les cohortes les plus jeunes, ces résultats indiquent qu’il faut s’attendre à des problèmes sévères d’obésité dans la population des USA dans un futur proche. Une corrélation positive entre l’IMC individuel et l’accroissement pourrait aggraver ce fait.

Modeling Cooperation in an Address-register-based Telephone/Face-to-face Survey

I analyze the effects of household sociodemography, interviewer performance in the current survey, and fieldwork characteristics on cooperation in a central telephone survey, where households with no publicly listed landline number receive face-to-face visits. Using the 2013 refreshment sample of the Swiss Household Panel, I employ household–interviewer cross-classified multilevel models and analyze first and later contacts separately. Some sociodemographic groups are less cooperative in the first contact only, others in both the first and later contacts, and still others in later contacts only. I offer recommendations about which households should be finalized at the first contact, which should be transferred to the face-to-face sample instead of being worked by telephone, and which interviewers should work which household groups.