On the Impossibility of Specification Testing of Interference Models Based on Exposure Mappings

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gao, Chao, Harshaw, Christopher, Sävje, Fredrik, Wang, Yitan
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913109899214848
author Gao, Chao
Harshaw, Christopher
Sävje, Fredrik
Wang, Yitan
author_facet Gao, Chao
Harshaw, Christopher
Sävje, Fredrik
Wang, Yitan
contents In order to estimate causal effects in a randomized experiment where spillovers are suspected to occur, analysts must posit a model of interference. The most popular class of interference models are those based on exposure mappings. In practice, it is rarely clear which interference model accurately captures the true nature of spillovers in the experiment. In response, researchers have developed specification tests which seek to determine whether a given interference model is correctly specified. In this context, Type I error is the rejection rate when the interference model is actually correct and Type II error is the acceptance rate when the interference model is incorrectly specified. While existing tests have been explicitly constructed to control Type I error, their Type II error remains less well understood. In this paper, we provide a strong impossibility result: any specification test for an exposure mapping model which aims to have power against a larger exposure mapping model has worst-case Type I and Type II errors that sum to one. This means that no specification test can provide uniformly better performance than the naive test which discards all data and rejects the null at random. Our negative result holds for all sample sizes, for uniformly bounded outcomes, and for alternatives which are maximally separated from the null. Informative specification tests must therefore further restrict the alternative model against which they seek to attain power. To this end, we provide a uniformly consistent test for differentiating no-interference from a network-linear-in-means model.
format Preprint
id arxiv_https___arxiv_org_abs_2605_09726
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle On the Impossibility of Specification Testing of Interference Models Based on Exposure Mappings
Gao, Chao
Harshaw, Christopher
Sävje, Fredrik
Wang, Yitan
Statistics Theory
Methodology
In order to estimate causal effects in a randomized experiment where spillovers are suspected to occur, analysts must posit a model of interference. The most popular class of interference models are those based on exposure mappings. In practice, it is rarely clear which interference model accurately captures the true nature of spillovers in the experiment. In response, researchers have developed specification tests which seek to determine whether a given interference model is correctly specified. In this context, Type I error is the rejection rate when the interference model is actually correct and Type II error is the acceptance rate when the interference model is incorrectly specified. While existing tests have been explicitly constructed to control Type I error, their Type II error remains less well understood. In this paper, we provide a strong impossibility result: any specification test for an exposure mapping model which aims to have power against a larger exposure mapping model has worst-case Type I and Type II errors that sum to one. This means that no specification test can provide uniformly better performance than the naive test which discards all data and rejects the null at random. Our negative result holds for all sample sizes, for uniformly bounded outcomes, and for alternatives which are maximally separated from the null. Informative specification tests must therefore further restrict the alternative model against which they seek to attain power. To this end, we provide a uniformly consistent test for differentiating no-interference from a network-linear-in-means model.
title On the Impossibility of Specification Testing of Interference Models Based on Exposure Mappings
topic Statistics Theory
Methodology
url https://arxiv.org/abs/2605.09726