In estimating p(,2) independent Poisson means,Clevenson and Zidek (1975) suggested a class of estimators which shrink the unbiased estimators to the origin.The suggested shrinkage estimators dominate the unbiased estimators under normalized squared error loss.Hwang (1982) has developed an identity for discrete exponential families which is applied to the estimation of parameters of Poisson and negative binomial distributions.