Q: When should I use a weight variable, and what kind should I use when?

A: Usually, for frequencies, use the scale weight (the weight that 'scales' up to the population total represented by the sample; also known as the expansion weight). For other applications, use the proportional weight (original weight variable * (sample size/population)).

• Weighting/ by Hector Malette (rev.) 2006-07-24
• Weight variables in the [Canadian] General social survey (GSS): how should they be used?/ with acknowledgements to Chuck Humphrey, Oct. 1999
• Weighting the [UK government] social surveys,/ Crockett, Alasdair, ESDS, rev. May 2007
• DuMouchel, William H. and Greg J. Duncan. Using sample survey weights in multiple regression analysis of stratified samples. Journal of the American Statistical Association 78:535-543, September 1983