arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1001.2102math.STstat.TH
收藏

非平稳非线性随机回归模型的条件最小二乘估计

Conditional least squares estimation in nonstationary nonlinear stochastic regression models

Christine Jacob

摘要:

设$\{Z_n\}$是一个实非平稳随机过程,使得$E(Z_n|{\mathcaligr F}_{n-1})\stackrel{\mathrm{a.s.}}{<}\infty$和$E(Z^2_n|{\mathcaligr F}_{n-1})\stackrel{\mathrm{a.s.}}{<}\infty$,其中$\{{\mathcaligr F}_n\}$是$σ$ -代数的增序列.假设有$E(Z_n|{\mathcaligr F}_{n-1})=g_n(θ_0,ν_0)=g^{(1)}_n(θ_0)+g^{(2)}_n(θ_0,ν_0)$,$θ_0\in{\mathbb{R}}^p$,$p<\infty$,$ν_0\in{\mathbb{R}}^q$和$q\leq\infty$,我们研究了$\hatθ_n:=\arg\min_θ\sum_{k=1}^n(Z_k-g_k({θ,\hatν}))^2λ_k^{-1}$的渐近性质,其中$λ_k$是${\mathcaligr F}_{k-1}$可测的,$\hatν=\{\hatν_k\}$是$ν_0$的估计序列,$g_n(θ,\hatν)$是$θ$中的Lipschitz,$g^{(2)}_n(θ_0,\hatν)-g^{(2)}_n(θ,\hatν)$相对于$g^{(1)}_n(θ_0)-g^{(1)}_n(θ)$渐近可忽略.首先,我们推广到这个非线性随机模型的$\{\hatθ_n\}$的强相容性的必要条件和充分条件的线性模型。为此,我们证明了一类下鞅的强大数定律。再次使用这个强的法律,我们得到的一般条件导致$\hatθ_n$的渐近分布。我们说明了分支过程的例子的理论结果,并扩展到拟似然估计也被认为是。

英文摘要:

Let $\{Z_n\}$ be a real nonstationary stochastic process such that $E(Z_n|{\mathcaligr F}_{n-1})\stackrel{\mathrm{a.s.}}{<}\infty$ and $E(Z^2_n|{\mathcaligr F}_{n-1})\stackrel{\mathrm{a.s.}}{<}\infty$, where $\{{\mathcaligr F}_n\}$ is an increasing sequence of $σ$-algebras. Assuming that $E(Z_n|{\mathcaligr F}_{n-1})=g_n(θ_0,ν_0)=g^{(1)}_n(θ_0)+g^{(2)}_n(θ_0,ν_0)$, $θ_0\in{\mathbb{R}}^p$, $p<\infty$, $ν_0\in{\mathbb{R}}^q$ and $q\leq\infty$, we study the asymptotic properties of $\hatθ_n:=\arg\min_θ\sum_{k=1}^n(Z_k-g_k({θ,\hatν}))^2λ_k^{-1}$, where $λ_k$ is ${\mathcaligr F}_{k-1}$-measurable, $\hatν=\{\hatν_k\}$ is a sequence of estimations of $ν_0$, $g_n(θ,\hatν)$ is Lipschitz in $θ$ and $g^{(2)}_n(θ_0,\hatν)-g^{(2)}_n(θ,\hatν)$ is asymptotically negligible relative to $g^{(1)}_n(θ_0)-g^{(1)}_n(θ)$. We first generalize to this nonlinear stochastic model the necessary and sufficient condition obtained for the strong consistency of $\{\hatθ_n\}$ in the linear model. For that, we prove a strong law of large numbers for a class of submartingales. Again using this strong law, we derive the general conditions leading to the asymptotic distribution of $\hatθ_n$. We illustrate the theoretical results with examples of branching processes, and extension to quasi-likelihood estimators is also considered.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑