Bias and Sensitivity Analyses for Linear Front-Door Models

The front-door model allows unbiased estimation of a total effect in the presence of unobserved confounding. This guarantee of unbiasedness hinges on a set of assumptions that can be violated in practice. We derive formulas that quantify the amount of bias for specific violations, and contrast them...

Full description

Bibliographic Details
Main Authors: Felix Thoemmes, Yongnam Kim
Format: Article
Language:English
Published: PsychOpen GOLD/ Leibniz Institute for Psychology 2023-09-01
Series:Methodology
Subjects:
Online Access:https://doi.org/10.5964/meth.9205
_version_ 1797320629797519360
author Felix Thoemmes
Yongnam Kim
author_facet Felix Thoemmes
Yongnam Kim
author_sort Felix Thoemmes
collection DOAJ
description The front-door model allows unbiased estimation of a total effect in the presence of unobserved confounding. This guarantee of unbiasedness hinges on a set of assumptions that can be violated in practice. We derive formulas that quantify the amount of bias for specific violations, and contrast them with bias that would be realized from a naive estimator of the effect. Some violations result in simple, monotonic increases in bias, while others lead to more complex bias, consisting of confounding bias, collider bias, and bias amplification. In some instances, these sources of bias can (partially) cancel each other out. We present ways to conduct sensitivity analyses for all violations, and provide code that performs sensitivity analyses for the linear front-door model. We finish with an applied example of the effect of math self-efficacy on educational achievement.
first_indexed 2024-03-08T04:45:47Z
format Article
id doaj.art-699322e6e9e74c2ea442a6f84aff5a28
institution Directory Open Access Journal
issn 1614-2241
language English
last_indexed 2024-03-08T04:45:47Z
publishDate 2023-09-01
publisher PsychOpen GOLD/ Leibniz Institute for Psychology
record_format Article
series Methodology
spelling doaj.art-699322e6e9e74c2ea442a6f84aff5a282024-02-08T10:51:08ZengPsychOpen GOLD/ Leibniz Institute for PsychologyMethodology1614-22412023-09-0119325628210.5964/meth.9205meth.9205Bias and Sensitivity Analyses for Linear Front-Door ModelsFelix Thoemmes0https://orcid.org/0000-0001-5689-2659Yongnam Kim1Cornell University, Ithaca, NY, USASeoul National University, Seoul, South KoreaThe front-door model allows unbiased estimation of a total effect in the presence of unobserved confounding. This guarantee of unbiasedness hinges on a set of assumptions that can be violated in practice. We derive formulas that quantify the amount of bias for specific violations, and contrast them with bias that would be realized from a naive estimator of the effect. Some violations result in simple, monotonic increases in bias, while others lead to more complex bias, consisting of confounding bias, collider bias, and bias amplification. In some instances, these sources of bias can (partially) cancel each other out. We present ways to conduct sensitivity analyses for all violations, and provide code that performs sensitivity analyses for the linear front-door model. We finish with an applied example of the effect of math self-efficacy on educational achievement.https://doi.org/10.5964/meth.9205causal inferencefront-doorbiasmeasurement errorsensitivity analysis
spellingShingle Felix Thoemmes
Yongnam Kim
Bias and Sensitivity Analyses for Linear Front-Door Models
Methodology
causal inference
front-door
bias
measurement error
sensitivity analysis
title Bias and Sensitivity Analyses for Linear Front-Door Models
title_full Bias and Sensitivity Analyses for Linear Front-Door Models
title_fullStr Bias and Sensitivity Analyses for Linear Front-Door Models
title_full_unstemmed Bias and Sensitivity Analyses for Linear Front-Door Models
title_short Bias and Sensitivity Analyses for Linear Front-Door Models
title_sort bias and sensitivity analyses for linear front door models
topic causal inference
front-door
bias
measurement error
sensitivity analysis
url https://doi.org/10.5964/meth.9205
work_keys_str_mv AT felixthoemmes biasandsensitivityanalysesforlinearfrontdoormodels
AT yongnamkim biasandsensitivityanalysesforlinearfrontdoormodels