Second Order Efficiency of the MLE with Respect to any Bounded Bowl-Shape Loss Function
Second Order Efficiency of the MLE with Respect to any Bounded Bowl-Shape Loss Function
复制标题
MLE 相对于任何有界碗形损失函数的二阶效率
DOI:
10.1214/aos/1176345005
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发表时间:
1980
期刊:
影响因子:
--
通讯作者:
H. Wieand
中科院分区:
文献类型:
--
作者:
J. Ghosh;B. K. Sinha;H. Wieand
Let X 1 , X 2 , .. be a sequence of i.i.d. random variables, each having
density f(x, θ 0 ) where {f(x, θ)} is a family of densities with respect to a
dominating measure µ. Suppose n ½ (θˆ - θ) and n ½ (T
- θ), where θˆ is the mle and T is any other efficient estimate, have Edgeworth
expansions up to o(n -1 ) uniformly in a compact neighbourhood of θ 0 . Then
(under certain regularity conditions) one can choose a function c(θ) such that θˆ =
θˆ + c(θˆ)/n satisfies Pθ 0 {-x 1 <
n ½ (θˆ' - θ 0 )(I(θ 0 )) ½ <
x 2 } > Pθ 0 {-x 1 ½ (T -
θ 0 )(I(θ 0 )) ½ 2 } + o(n -1 ),
for all x 1 , x 2 > 0. This result implies the second order efficiency of the
mle with respect to any bounded loss function Ln(θ, a) = h(n ½ (a - θ)),
which is bowl-shaped i.e., whose minimum value is zero at a - θ = 0 and which increases as |a -
θ| increases. This answers a question raised by C. R. Rao (Discussion on Professor Efron's
paper).