I read a lot of sources concerning stein's estimator and James-Stein estimator. Unfortunately, a lot of sources do not write the correct formulas of each estimator. And so I am now confused!!
Kindly, can someone explain me in details the difference between Stein's and James-Stein estimators.
1) How James-Stein (1962) estimator differs from Stein's estimator(1955).*
2) Why James-Stein is developed in order to improve the Stein's estimator? So what are the disadvantages of Stein's estimator?
3) What are the correct formulas of each one?
4) Why Stein's estimator and James-Stein estimator are considered as shrinkage estimators?
Any brief explanation will be very appreciated!