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arXiv 2102.07203math.STstat.TH
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半监督高维回归模型的改进估计

Improved Estimators for Semi-supervised High-dimensional Regression Model

Ilan Livne, David Azriel, Yair Goldberg

摘要:

我们研究了半监督环境下的线性高维回归模型,其中对于许多观测,只有协变量的向量$X$给出,没有响应$Y$。我们不做任何稀疏性假设的系数向量,并旨在估计$\mathrm{Var}(Y|X)$。我们提出了一个估计,这是无偏的,一致的,渐近正态的。该估计量可以通过添加由未标记数据产生的零估计量来改进。添加零估计量不会影响偏倚,并且可能会降低方差。为了达到最佳的改善,许多零估计应该使用,但这提出了估计许多参数的问题。因此,我们引入协变量选择算法,以确定应使用哪些零估计,以改善上述估计。我们进一步说明我们的方法,其他估计,并提出了一个算法,提高估计任何给定的方差估计。我们的理论结果证明在模拟研究。

英文摘要:

We study a linear high-dimensional regression model in a semi-supervised setting, where for many observations only the vector of covariates $X$ is given with no response $Y$. We do not make any sparsity assumptions on the vector of coefficients, and aim at estimating $\mathrm{Var}(Y|X)$. We propose an estimator, which is unbiased, consistent, and asymptotically normal. This estimator can be improved by adding zero-estimators arising from the unlabelled data. Adding zero-estimators does not affect the bias and potentially can reduce variance. In order to achieve optimal improvement, many zero-estimators should be used, but this raises the problem of estimating many parameters. Therefore, we introduce covariate selection algorithms that identify which zero-estimators should be used in order to improve the above estimator. We further illustrate our approach for other estimators, and present an algorithm that improves estimation for any given variance estimator. Our theoretical results are demonstrated in a simulation study.

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。

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