arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2211.07533stat.MLcs.LG
收藏

通过深度神经网络实现广义平衡权重

Generalized Balancing Weights via Deep Neural Networks

NTT DATA Mathematical Systems Inc.(NTT数据数学系统公司)

Yoshiaki Kitazawa

AI总结:

本文提出 Neural Balancing Weights(NBW),通过优化 α-散度的变分表示直接估计密度比,以处理离散与连续混合干预下的多维因果效应估计问题。

摘要:

从观测数据中估计因果效应是许多领域的核心问题。一种通用方法是使用权重平衡协变量,使数据分布模拟随机化。我们提出广义平衡权重,即 Neural Balancing Weights(NBW,神经平衡权重),用于估计离散与连续干预的任意混合所产生的因果效应。这些权重通过优化 f-散度的变分表示,直接估计源分布与平衡分布之间的密度比而获得。为此,我们选择 α-散度,因为它具有高效优化特性:其估计量的样本复杂度独立于真实值,并具有无偏的小批量梯度;此外,它还有利于缓解梯度消失问题。我们还提供了以下两种估计平衡权重的方法:改善平衡权重的泛化性能,以及检查由权重改变后的分布的平衡性。最后,我们将权重对样本量的要求作为平衡多维数据时维数灾难的一般问题加以讨论。本研究为利用变分 f-散度估计多维数据的平衡权重提供了一种基础方法。

英文摘要:

Estimating causal effects from observational data is a central problem in many domains. A general approach is to balance covariates with weights such that the distribution of the data mimics randomization. We present generalized balancing weights, Neural Balancing Weights (NBW), to estimate the causal effects of an arbitrary mixture of discrete and continuous interventions. The weights were obtained through direct estimation of the density ratio between the source and balanced distributions by optimizing the variational representation of $f$-divergence. For this, we selected $α$-divergence as it presents efficient optimization because it has an estimator whose sample complexity is independent of its ground truth value and unbiased mini-batch gradients; moreover, it is advantageous for the vanishing-gradient problem. In addition, we provide the following two methods for estimating the balancing weights: improving the generalization performance of the balancing weights and checking the balance of the distribution changed by the weights. Finally, we discuss the sample size requirements for the weights as a general problem of a curse of dimensionality when balancing multidimensional data. Our study provides a basic approach for estimating the balancing weights of multidimensional data using variational $f$-divergences.

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。

↑