Nonresponse in surveys may result in a distortion of the distribution of interest. In a panel survey the participation behavior in later waves is different from the participation behavior at the start. With register data that cover also the information for non-respondents one can observe a fade...

Flexibles Carsharing bietet in den Städten eine Alternative zum privaten PKW-Besitz. Der mögliche Beitrag dieser Dienstleistungen zu einer Reduktion der Autoanzahl wird aber immer wieder kontrovers diskutiert. Die empirische Datenbasis zu dieser Frage ist bisher noch relativ klein. Die...

This report describes the design, data, and main results of an online survey (i.e., the "Judging Without Knowing" survey) that was conducted between October 2017 and June 2018 with more than 2,000 registered members on Clickworker (a commercial survey company in Germany). The survey was...

This paper investigates if significant differences exist between online and paper & pencil participants in a quarterly business survey in the German business-related services sector when respondents may freely choose to respond either online or by more conventional methods. It also analyzes the...

We propose a novel view of selection bias in longitudinal surveys. Such bias may arise from initial nonresponse in a probability sample, or it may be caused by self-selection in an internet survey. A contraction theorem from mathematical demography is used to show that an initial bias can...