Samenvatting
The panel sampling design has a great impact on three panel problems.First the design determines to which extent the problem of a changing population is overcome, i.e. to which extent the panel sample is updated. Next the panel design may contribute to combatting the other two panel problems, selective attrition and panel conditioning.The impact of the interviewing frequency is briefly treated.Furthermore it is argued that persons or plans should be followed, not aggregates like households or firms. Some obstacles are mentioned that one may encounter when drawing, updating and maintaining the sample.