arXiv Statistics ML

New explanations and inference for least angle regression

The paper introduces a new inference framework for least angle regression (LAR), clarifying its behavior and providing a formal stopping rule. It shows that LAR estimates non‑zero population correlations as independent normal variables, while zero correlations follow a non‑normal joint distribution, enabling variable importance interpretation. A modified bootstrap method is proposed to quantify uncertainty and assess variable entry, with results validated by simulation and data examples.

arXiv Machine Learning
5d ago

Pro-Active Inference

The paper introduces Pro-Active Inference (PAI), a method for efficiently estimating a population mean when only a subset of outcomes can be observed. PAI proactively selects which observation to label next from a covariate pool, updating machine‑learning predictions online, and provides finite‑sample unbiasedness, asymptotic validity, and an improved variance estimator. Experiments on eight datasets show that PAI outperforms Sequential Active Inference in most settings, while diagnostics reveal when additional adaptivity is beneficial or detrimental.

By Skyler Wu, Yash Nair, Antoine Maechler, Emmanuel J. Cand\`es
arXiv Statistics ML
Aug 25

Model-Agnostic Covariate-Assisted Inference on Partially Identified Causal Effects

The paper introduces a model‑agnostic inference framework for partially identified causal effects that leverages covariate information without requiring discrete covariates or accurate conditional distribution estimates. Using duality theory for optimal transport, the method delivers uniformly valid inference in randomized experiments, is doubly robust in observational settings, achieves asymptotic unbiasedness when nuisance parameters converge semiparametrically, and allows multiplier‑bootstrap selection of covariates and models while remaining computationally efficient. Empirical applications show the approach consistently narrows identified sets and confidence intervals without imposing extra structural assumptions.

By Wenlong Ji, Lihua Lei, Asher Spector
arXiv Machine Learning
Jun 9

Partial Identification under Missing Data Using Weak Shadow Variables from Pretrained Models

arXiv:2602. 16061v2 Announce Type: replace-cross Abstract: Estimating population quantities such as mean outcomes from user feedback is fundamental to platform evaluation and social science, yet feedback is often missing not at random (MNAR): users with stronger opinions are more likely to respond, so standard estimators are biased and the estimand is not identified without additional assumptions.

By Hongyu Chen, David Simchi-Levi, Ruoxuan Xiong
arXiv Statistics ML
5d ago

Agentic Distributional Regression: Conditional Density Estimation through Agent-Written Programs

The paper introduces Agentic Distributional Regression (ADR), a method that uses a language‑model agent to generate a short program estimating conditional densities from iid data. The agent constructs the estimator from a library of probability distributions, producing a parametric, mixture, or multivariate factorization whose parameters are explicit functions of covariates. The authors provide finite‑sample error bounds, an oracle inequality for model selection, and show asymptotic normality of fitted constants, with simulation results indicating ADR outperforms other methods on twelve real datasets and a new post‑training dataset.

By Lorenzo Tedesco (University of Bergamo)