I have a population of about 7200 businesses from which to sample 2100 for a survey.
The sample is to be stratified, but I have no information whatsoever on the usual way to stratify this population, except that it is usually based on revenue intervals.
Rather than just finding a good stratification by trial and error, I was wondering if there is an algorithm which creates strata based on minimisation of variance within strata.
I've tried running my data through a clustering algorithm, but it doesn't work as no clear revenue intervals emerge from the clusters.
Is there some other algorithm or procedure to go by?
I'm using R or SAS.
Thanks in advance.