The Usefulness of Panel Data to Understand Changes - the German Approach
ZUMKELLER D and CHLOND B, University of Karlsruhe, Germany
The transport development of the recent years has been characterized mainly by external factors i.e. non-transport factors. Included in these factors are amongst other things the age and household structure, the unification of Germany~ the integration of
The transport development of the recent years has been characterized mainly by external factors i.e. non-transport factors. Included in these factors are amongst other things the age and household structure, the unification of Germany~ the integration of Germany in Western Europe and the upheaval in Easteren Europe and finally changes in working pattems and increasing leisure times. In view of these developments endogeneous interventions i.e. interventions in the transport system ("telematics, public transport improvements, 30 km/h speed zones" etc.) aim at an improvement of the general transport conditions. It is supposed that these endogenous interventions can actually initiate the intended behavioural changes. These changes in behaviour become clearer if one tries to understand them as the result of continuous changes of the temporal, monetary and organisational budgets and regimes as well as the result of changes in the personal status. In addition to the observation of a (static) status quo the observation of the (dynamic) process of behavioural changes is initiated by these previously mentioned endogenoues or exogenous factors. If one follows such a manner of exploration for the estimation of future developments, then the panel survey method must be introduced alongside the snapshot.
A panel survey distinguishes from cross-sectional or snapshot surveys by selecting a sample of persons at the beginning of the time series and retaining the same individuals within the sample several times (panel in its original sense, at discrete points in time). Another idea involved with a panel is to observe people over a period which normally is representing a commonly accepted cycle of typical human behaviour (i.e. a week as a continuum, this represents the steady case of a longitudinal observation). Not only because of the methodological and analytical possibilities of panel data there has been the idea to establish a panel on travel behaviour also in Germany. Altogether there are three different but also related purposes of the panel.
Association for European Transport