PETRA - Weights. PETRA working papers no. 3

摘要

The procedure involves a minimum of 1,000 individuals being interviewed by telephone on a monthly basis, with the exception being the month of July. The participants are drawn at random to create a representative sample of the total population of people aged between 16 and 74 years of age. The response rate fluctuates between 61% and 66%, which generally results in approximately 1,100 useful interviews with a sample size of 1,800 persons, and approximately 1,500 useful interviews with a sample size of 2,300 persons. The respondents are asked questions about trips undertaken the day immediately prior to the interview, and any longer trips (more than 100 km) undertaken in the month before the interview. Further, a number of questions relating to the interview and the family are asked. (EG)