Second Order Efficiency of the MLE with Respect to any Bounded Bowl-Shape Loss Function
Ghosh, J. K. ; Sinha, B. K. ; Wieand, H. S.
Ann. Statist., Tome 8 (1980) no. 1, p. 506-521 / Harvested from Project Euclid
Let $X_1, X_2, \cdots$ be a sequence of i.i.d. random variables, each having density $f(x, \theta_0)$ where $\{f(x, \theta)\}$ is a family of densities with respect to a dominating measure $\mu$. Suppose $n^{\frac{1}{2}}(\hat{\theta} - \theta)$ and $n^{\frac{1}{2}}(T - \theta)$, where $\hat{\theta}$ is the mle and $T$ is any other efficient estimate, have Edgeworth expansions up to $o(n^{-1})$ uniformly in a compact neighbourhood of $\theta_0$. Then (under certain regularity conditions) one can choose a function $c(\theta)$ such that $\hat{\theta}' = \hat{\theta} + c(\hat{\theta})/n$ satisfies $P_{\theta_0} \{-x_1 \leqslant n^{\frac{1}{2}}(\hat{\theta}' - \theta_0)(I(\theta_0))^{\frac{1}{2}} \leqslant x_2\} \\ \geqslant P_{\theta_0}\{-x_1 \leqslant n^{\frac{1}{2}}(T - \theta_0)(I(\theta_0))^{\frac{1}{2}} \leqslant x_2\} + o(n^{-1}),$ for all $x_1, x_2 \geqslant 0$. This result implies the second order efficiency of the mle with respect to any bounded loss function $L_n(\theta, a) = h(n^{\frac{1}{2}}(a - \theta))$, which is bowl-shaped i.e., whose minimum value is zero at $a - \theta = 0$ and which increases as $|a - \theta|$ increases. This answers a question raised by C. R. Rao (Discussion on Professor Efron's paper).
Publié le : 1980-05-14
Classification:  Maximum likelihood estimate,  second order efficiency,  Edgeworth expansion,  Bayes test,  Rao-Blackwell theorem,  bowl-shaped loss function,  62B10,  62F20
@article{1176345005,
     author = {Ghosh, J. K. and Sinha, B. K. and Wieand, H. S.},
     title = {Second Order Efficiency of the MLE with Respect to any Bounded Bowl-Shape Loss Function},
     journal = {Ann. Statist.},
     volume = {8},
     number = {1},
     year = {1980},
     pages = { 506-521},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1176345005}
}
Ghosh, J. K.; Sinha, B. K.; Wieand, H. S. Second Order Efficiency of the MLE with Respect to any Bounded Bowl-Shape Loss Function. Ann. Statist., Tome 8 (1980) no. 1, pp.  506-521. http://gdmltest.u-ga.fr/item/1176345005/