EWCS 2010 - Weighting

As in previous waves of the EWCS three types of weights need to be applied to ensure that results based on the 5th EWCS data can be considered representative for workers in Europe.

1. Selection probability weights
   Because of the way the sampling process is designed, people in households with fewer workers have a greater chance of being selected into the sample than people in households with more workers. For example, in a household with one person in employment, the probability of this person to be selected is 100%, whereas it drops to 50% for persons in a household with two people in employment. Selection probability weights (or design weights) are constructed to correct for this.
2. Post-stratification weights
   Because of differences in the willingness and availability to participate in the survey certain groups are overrepresented and other groups are underrepresented in the EWCS sample. To ensure that the results accurately reflect the population of workers in each country post-stratification weighting is needed. The weights are calculated by comparing the EWCS to the Labour Force Survey (Eurostat) with regard to the gender, age, region, occupation and sector of economic activity of the respondents. 
3. Supra-national weights
   The differences between countries in the size of their workforce, are not (fully) reflected in the sample size in each country. To ensure that larger countries weigh heavier in the EU level results, supra-national weights need to be applied when performing analyses on the European level.

For more information please see the Weighting Report, [.pdf, 3.7MB, in English only].