The variance of causal effect estimators for binary v-structures

Adjusting for covariates is a well-established method to estimate the total causal effect of an exposure variable on an outcome of interest. Depending on the causal structure of the mechanism under study, there may be different adjustment sets, equally valid from a theoretical perspective, leading t...

Full description

Bibliographic Details
Main Authors: Kuipers Jack, Moffa Giusi
Format: Article
Language:English
Published: De Gruyter 2022-05-01
Series:Journal of Causal Inference
Subjects:
Online Access:https://doi.org/10.1515/jci-2021-0025
_version_ 1797998372873830400
author Kuipers Jack
Moffa Giusi
author_facet Kuipers Jack
Moffa Giusi
author_sort Kuipers Jack
collection DOAJ
description Adjusting for covariates is a well-established method to estimate the total causal effect of an exposure variable on an outcome of interest. Depending on the causal structure of the mechanism under study, there may be different adjustment sets, equally valid from a theoretical perspective, leading to identical causal effects. However, in practice, with finite data, estimators built on different sets may display different precisions. To investigate the extent of this variability, we consider the simplest non-trivial non-linear model of a v-structure on three nodes for binary data. We explicitly compute and compare the variance of the two possible different causal estimators. Further, by going beyond leading-order asymptotics, we show that there are parameter regimes where the set with the asymptotically optimal variance does depend on the edge coefficients, a result that is not captured by the recent leading-order developments for general causal models. As a practical consequence, the adjustment set selection needs to account for the relative magnitude of the relationships between variables with respect to the sample size and cannot rely on purely graphical criteria.
first_indexed 2024-04-11T10:47:40Z
format Article
id doaj.art-75e4fda807ad4b67a9b93123ff2601bd
institution Directory Open Access Journal
issn 2193-3685
language English
last_indexed 2024-04-11T10:47:40Z
publishDate 2022-05-01
publisher De Gruyter
record_format Article
series Journal of Causal Inference
spelling doaj.art-75e4fda807ad4b67a9b93123ff2601bd2022-12-22T04:29:00ZengDe GruyterJournal of Causal Inference2193-36852022-05-011019010510.1515/jci-2021-0025The variance of causal effect estimators for binary v-structuresKuipers Jack0Moffa Giusi1Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, SwitzerlandDepartment of Mathematics and Computer Science, University of Basel, Basel, SwitzerlandAdjusting for covariates is a well-established method to estimate the total causal effect of an exposure variable on an outcome of interest. Depending on the causal structure of the mechanism under study, there may be different adjustment sets, equally valid from a theoretical perspective, leading to identical causal effects. However, in practice, with finite data, estimators built on different sets may display different precisions. To investigate the extent of this variability, we consider the simplest non-trivial non-linear model of a v-structure on three nodes for binary data. We explicitly compute and compare the variance of the two possible different causal estimators. Further, by going beyond leading-order asymptotics, we show that there are parameter regimes where the set with the asymptotically optimal variance does depend on the edge coefficients, a result that is not captured by the recent leading-order developments for general causal models. As a practical consequence, the adjustment set selection needs to account for the relative magnitude of the relationships between variables with respect to the sample size and cannot rely on purely graphical criteria.https://doi.org/10.1515/jci-2021-0025causalitycovariate adjustmentstructure learningbayesian networksprobability theory62h22
spellingShingle Kuipers Jack
Moffa Giusi
The variance of causal effect estimators for binary v-structures
Journal of Causal Inference
causality
covariate adjustment
structure learning
bayesian networks
probability theory
62h22
title The variance of causal effect estimators for binary v-structures
title_full The variance of causal effect estimators for binary v-structures
title_fullStr The variance of causal effect estimators for binary v-structures
title_full_unstemmed The variance of causal effect estimators for binary v-structures
title_short The variance of causal effect estimators for binary v-structures
title_sort variance of causal effect estimators for binary v structures
topic causality
covariate adjustment
structure learning
bayesian networks
probability theory
62h22
url https://doi.org/10.1515/jci-2021-0025
work_keys_str_mv AT kuipersjack thevarianceofcausaleffectestimatorsforbinaryvstructures
AT moffagiusi thevarianceofcausaleffectestimatorsforbinaryvstructures
AT kuipersjack varianceofcausaleffectestimatorsforbinaryvstructures
AT moffagiusi varianceofcausaleffectestimatorsforbinaryvstructures