Many might first think of Bayesian statistics.
"Synthetic estimates" may come to mind. (Ken Brewer included a chapter on synthetic estimation: Brewer, KRW (2002), Combined survey sampling inference: Weighing Basu's elephants, Arnold: London and Oxford University Press.)
My first thought is for "borrowing strength." I would say that if you do that, then you are using small area estimation (SAE). That is, I define SAE as any estimation technique for finite population sampling which "borrows strength."
Some references are given below.
What do you think?
http://www.wiley.com/WileyCDA/WileyTitle/productCd-0471413747.html
http://projecteuclid.org/euclid.ss/1177010647
http://www.amstat.org/sections/SRMS/Proceedings/papers/1999_115.pdf
http://js.iasri.res.in/jisas/jsp/volume/vol57/jnkrao.pdf
Article Quasi-Cutoff Sampling and Simple Small Area Estimation with ...