HOIF: Higher-Order Influence Function Estimators for the Average Treatment Effect

Implements Higher-Order Influence Function (HOIF) estimators of the Average Treatment Effect (ATE), following Robins et al. (2008) <doi:10.1214/193940307000000527>, Liu et al. (2017) <doi:10.48550/arXiv.1705.07577> and Liu and Li (2023) <doi:10.48550/arXiv.2302.08097>. Estimators of any order are supported, with optional covariate basis transformations (B-splines, Fourier) and optional K-fold sample splitting (cross-fitting) for improved finite-sample performance. The core higher-order U-statistics are computed exactly via the 'ustats' package, an R interface to the 'Python' package 'u-stats'; the underlying algorithm and its computational complexity are analyzed in Chen, Zhang and Liu (2025) <doi:10.48550/arXiv.2508.12627>. A pure R implementation (up to order 6) is also provided as a fallback that does not require 'Python'.

Version:	0.2.0
Depends:	R (≥ 4.0.0)
Imports:	splines, corpcor, SMUT, ustats (≥ 0.1.5)
Suggests:	MASS, testthat (≥ 3.0.0), reticulate, knitr, rmarkdown
Published:	2026-06-24
DOI:	10.32614/CRAN.package.HOIF (may not be active yet)
Author:	Xingyu Chen [aut, cre], Lin Liu [aut]
Maintainer:	Xingyu Chen <xingyuchen0714 at sjtu.edu.cn>
BugReports:	https://github.com/cxy0714/HOIF/issues
License:	MIT + file LICENSE
URL:	https://cxy0714.github.io/HOIF/, https://github.com/cxy0714/HOIF
NeedsCompilation:	no
SystemRequirements:	For the default Python backend: Python (>= 3.11) with the 'u-stats', 'numpy' and 'torch' packages (provisioned automatically on first use via 'reticulate', or via ustats::setup_ustats()). Not needed when pure_R_code = TRUE.
Language:	en-US
Materials:	NEWS
CRAN checks:	HOIF results

Documentation:

Reference manual:	HOIF.html , HOIF.pdf
Vignettes:	Introduction to HOIF: Higher-Order Influence Function Estimators for the ATE (source, R code)

Downloads:

Package source:	HOIF_0.2.0.tar.gz
Windows binaries:	r-devel: not available, r-release: HOIF_0.2.0.zip, r-oldrel: not available
macOS binaries:	r-release (arm64): HOIF_0.2.0.tgz, r-oldrel (arm64): HOIF_0.2.0.tgz, r-release (x86_64): HOIF_0.2.0.tgz, r-oldrel (x86_64): HOIF_0.2.0.tgz

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