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Bibliographic Details
Main Authors: Barua, Ananyabrata, Basu, Ayanendranath
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2512.03021
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author Barua, Ananyabrata
Basu, Ayanendranath
author_facet Barua, Ananyabrata
Basu, Ayanendranath
contents Real-world measurements often comprise a dominant signal contaminated by a noisy background. Robustly estimating the dominant signal in practice has been a fundamental statistical problem. Classically, mixture models have been used to cluster the heterogeneous population into homogeneous components. Modeling such data with fully parametric models risks bias under misspecification, while fully nonparametric approaches can dissipate power and computational resources. We propose a middle path: a semiparametric method that models only the dominant component parametrically and leaves the background completely nonparametric, yet remains computationally scalable and statistically robust. So instead of outlier downweighting, traditionally done in robust statistics literature, we maximize the observed likelihood such that the noisy background is absorbed by the nonparametric component. Computationally, we propose a new approximate FFT-accelerated likelihood maximization algorithm. Empirically, this FFT plug-in achieves order-of-magnitude speedups over vanilla weighted EM while preserving statistical accuracy and large sample properties.
format Preprint
id arxiv_https___arxiv_org_abs_2512_03021
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Semiparametric Robust Estimation of Population Location
Barua, Ananyabrata
Basu, Ayanendranath
Computation
Real-world measurements often comprise a dominant signal contaminated by a noisy background. Robustly estimating the dominant signal in practice has been a fundamental statistical problem. Classically, mixture models have been used to cluster the heterogeneous population into homogeneous components. Modeling such data with fully parametric models risks bias under misspecification, while fully nonparametric approaches can dissipate power and computational resources. We propose a middle path: a semiparametric method that models only the dominant component parametrically and leaves the background completely nonparametric, yet remains computationally scalable and statistically robust. So instead of outlier downweighting, traditionally done in robust statistics literature, we maximize the observed likelihood such that the noisy background is absorbed by the nonparametric component. Computationally, we propose a new approximate FFT-accelerated likelihood maximization algorithm. Empirically, this FFT plug-in achieves order-of-magnitude speedups over vanilla weighted EM while preserving statistical accuracy and large sample properties.
title Semiparametric Robust Estimation of Population Location
topic Computation
url https://arxiv.org/abs/2512.03021