In the Labour Force Survey (LFS) of the European Union, like in many other household surveys, there is a growing trend towards the use of multiple data collection modes. While comparing computer-assisted personal interviewing (CAPI) and computer-assisted telephone interviewing (CATI) have already been used side-by-side in the past, computer assisted web interviewing (CAWI) is currently being prepared as an additional mode in many countries. One of the main concerns associated with the use of multiple data collection modes is that mode effects could lead to measurement bias. Despite the vast literature on mode effects in survey research, there are relatively few studies on the importance of mode effects in the specific case of Labour Force Surveys. Labour Force Surveys differ from other population surveys in several respects: For example, they have a particularly long questionnaire, they are sometimes carried out with mandatory response, they predominantly contain factual, non-sensitive questions, and many of the questions include a long lists of response items.
Based on research carried out in the European project "Data collection for social surveys using multiple modes" carried out by five National Statistical Offices (Germany, the Netherlands, Finland, the United Kingdom, and Norway), the contribution identifies likely sources of mode effects in the specific setting of the LFS. Furthermore analyses from a randomized experiment of the German LFS will be presented comparing CAPI, CATI, CAWI, as well as paper-and-pencil self-completion. Based on these preliminary findings, we discuss which aspects of mode..