# Sampling: When is it better to use Simple Random Sampling rather than Stratified Random Sampling?

I know that stratified random sampling is almost always preferred over simple random sampling, but I have also read that the Variance of sample mean (x-bar) from stratified random sampling could sometimes be larger than the Variance of x-bar under simple random sample. In those cases, SRS might a better method compared to stratified random sampling.

Logically, it seems to make sense, but I'm wondering if there's a more mathematical way to explain this, and maybe a (simple) real life example?

• stratified random sampling is almost always preferred over simple random sampling who said that? Do you have any sources for these and other claims? – user2974951 Jul 17 '19 at 11:06