Eurobarometer Data Service

Weighting overview

The Candidate Countries Eurobarometer, in accordance standard series, provide two types of weighting. For post-stratification weighting  (also refered to as redressment or non-response weighting) a comparison between the sample and the universe was carried out for each country. Gallup applied the universe description as derived from population data from national statistics. As such in all countries, gender, age, region NUTS 2, settlement size, household size, and education level were introduced in the iteration procedure (raking procedure or rim weighting). 

The population size weight corrects for the fact that most countries have almost identical sample sizes, no matter how large or small their populations are. They ensure that each country is represented in proportion to its population size when the group of all countries is the object of study (i.e. candidate countries averages). For this purpose Gallup applied the official population figures as provided by national statistics.

Official EC publications (reports) are usually based on weighted data.

Post-stratification weights

  • WEIGHT COUNTRY is supposed to be applied when individual countries are analyzed separately. It reproduces the real number of cases for each country.

Population size weights (including post-stratification)

  • WEIGHT CC 13 is mandatory when analysing the group of all candidate countries as a whole.    

  • WEIGHT MEMBER COUNTRIES is mandatory when analysing the group of the ten new members as of the 2004 enlargement as a whole. The remaining candidates Bulgaria, Romania and Turkey are excluded from calculation. This weight is only available for the surveys 2003.5 and 2004.1.

Note:

For UNIVARIATE (descriptive) analysis the application of the Eurobarometer POST-STRATIFICATION WEIGHTS is recommended, the application of the POPULATION SIZE WEIGHTS mandatory. Official Eurobarometer reports are based on weighted data. 

Recommended for reading

Häder, Sabine; Gabler, Siegfried (1997): Deviations from the Population and Optimal Weights, in: Saris, Willem E.; Kaase, Mas (eds.): ZUMA Nachrichten Spezial. Band 2, Mannheim.

Arzheimer, Kai (2009): Gewichtungsvariation. In: Schoen, Harald; Rattinger, Hans; Gabriel, Oscar (Hrsg.): Vom Interview zur Analyse. Baden-Baden. S. 361-388.

Gabler, Siegfried; Ganninger, Matthias (2010): Gewichtung. In: Wolf, Christof; Best, Henning (Hrsg.): Handbuch der sozialwissenschaftlichen Datenanalyse: VS Verlag für Sozialwissenschaften, S. 143-164.