Can the cross-sectional self-completion interview weight variable be used to estimate the real population distribution at the Local Authority level?
We're currenlty working on a study, for which we need to know the percentage of each religous group in every LA unit. The Census data seem to have information only about England and Wales (no information is avaiable for Norhtern Ireland and Scotland). Also, small reliogus groups do not seem to be found in Census either. So, in each wave, we've used the cross-sectional self-completion interview weights to weigh the number of resondents in the corresponding group and the total number in every LA unit. We then calculate the percentages based on this pair of numbers in every unit. Can those numbers represent the real populaton distribution (by religon) at the LA level?
Updated by Olena Kaminska over 1 year ago
Dear Jing Shen,
Thank you for your question. This question is rather a statistical one, and I can only answer about Understanding Society estimates.
I understand (though I am not sure my understanding is correct) that you estimate religious groups in each LA area using Understanding Society. This may be possible using our data, but a few statistical points need to be kept in mind: firstly, pay attention to confidence intervals - I expect them to be relatively large as you will be working with relatively small sample sizes (your sample size will that of each LA); also as you are looking at the proportions occurring towards the tail of a distribution (e.g. less than 5%) I would suggest to use appropriate confidence intervals for the extreme proportions - these will be larger and often skewed to one side. Of course your estimates should be weighted.
Hope this helps,