arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2106.03340cs.LG

Instrument Space Selection for Kernel Maximum Moment Restriction

Australian National University(澳大利亚国立大学);MPI for Intelligent Systems(马克斯·普朗克智能系统研究所);University of Tokyo(东京大学)

Rui Zhang, Krikamol Muandet, Bernhard Schölkopf, Masaaki Imaizumi

英文摘要:

Kernel maximum moment restriction (KMMR) recently emerges as a popular framework for instrumental variable (IV) based conditional moment restriction (CMR) models with important applications in conditional moment (CM) testing and parameter estimation for IV regression and proximal causal learning. The effectiveness of this framework, however, depends critically on the choice of a reproducing kernel Hilbert space (RKHS) chosen as a space of instruments. In this work, we presents a systematic way to select the instrument space for parameter estimation based on a principle of the least identifiable instrument space (LIIS) that identifies model parameters with the least space complexity. Our selection criterion combines two distinct objectives to determine such an optimal space: (i) a test criterion to check identifiability; (ii) an information criterion based on the effective dimension of RKHSs as a complexity measure. We analyze the consistency of our method in determining the LIIS, and demonstrate its effectiveness for parameter estimation via simulations.

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。

↑