Biostatistics · Harvard Chan School

Haoyu Yang

Postdoctoral Research Fellow in Biostatistics. I build methods that extract more reliable discovery from the data we already have — and prove they stay valid even when the AI-generative model is wrong, the populations are heterogeneous, or the formulation of the statistic is complex.

Currently, I'm on the job market. Please don't hesitate to contact me if you are interested in my research or would like to share any ideas 🥳!

Portrait of Haoyu Yang
01

Recent News

2026
Our paper “A tail likelihood ratio method for large-scale causal mediation tests in epigenome-wide studies” has been accepted in the Journal of the American Statistical Association. 🎉
With R. Wang, Y. Lin and X. Lin · Software: TLR ↗
2026
Our paper “Design strategies for networked experiments via interference balancing” is published online in the Journal of Business & Economic Statistics.
With Y. Qin, Y. Yu and Y. Li · Read the paper ↗ · Software: NetRR ↗
02

About

I am a Postdoctoral Research Fellow in the Department of Biostatistics at the Harvard T.H. Chan School of Public Health, working with Professor Xihong Lin.

My work starts from one observation: Data is rich and diverse, yet each has its own problems. Every dataset contains more information than a standard or naive analysis extracts.

Some of it sits in missing measurements — the 90% of a biobank whose proteome was never assayed, though its genotypes and clinical records are complete. Some sits in heterogenous populations - the target population is too small, and the available source populations are too heterogeneous to combine. Some is discarded by the analysis itself, when half a million hypothesis tests are evaluated one at a time, and everything the ensemble knows is thrown away. And some information is ignored when participants are enrolled, by a design that leaves balance to chance.

I build methods that convert this potential information into scientific discovery. The difficulty is that each of these sources is untrustworthy in its own specific way — a generative model can be misspecified, another population can carry different biology, a composite null distribution is hard to characterize — which is why the interesting part of the problem is statistical rather than computational.

Before Harvard, I earned my Ph.D. in Statistics at Renmin University of China.

Position
Postdoctoral Research Fellow
Affiliation
Harvard T.H. Chan School
Department of Biostatistics
Location
Boston, USA
Research Interests
Biostatistics Statistical Genetics Robust inference with AI-generated Data Synthetic Data Transfer Learning Multiple Testing Composite Null Hypotheses Causal Inference Causal Mediation Analysis Genome-wide Association Studies Proteomics Adaptive Randomization Network Interference
Data I work with
UK Biobank
About half a million UK adults with genomic, proteomic and health-record data.
Used in: Syn-PALM [12] · TransSynPALM · HEART [16]
All of Us
A diverse US research cohort with whole genomes and electronic health records.
Used in: Variant callers [3] · TransSynPALM · HEART [16]
Nurses' Health Study
121,700 female nurses followed since 1976, with diet questionnaires and plasma metabolomics.
Used in: MultiSynSurr [17]
Normative Aging Study
The VA's longitudinal cohort of older men, with blood DNA methylation.
Used in: TLR [1] · Causal mediation review [4]
03

Education & Appointment

Jul 2023 — Present
Postdoctoral Research Fellow
Harvard University · Department of Biostatistics — Boston, USA
Advisor: Xihong Lin
Sep 2018 — Jun 2023
Ph.D. in Statistics
Renmin University of China — Beijing, China
Advisor: Yang Li
Sep 2014 — Jun 2018
B.S. in Mathematics & Applied Mathematics
Tianjin University — Tianjin, China
Minor in Financial Management
04

Research

Biomedical research routinely discards four critical sources of information: unmeasured samples, excluded populations, the hidden structure of large-scale testing, and the study’s own design. My research builds methodological frameworks for each, united by a single guarantee: borrowing strength must never cost you the error rate.

01 · Multiplicity

Multiplicity is a blessing.

When a study runs half a million tests, the ensemble of statistics is enormously informative about which hypotheses are true. I turn the multiplicity into the thing that makes the test nearly optimal.

M-DACT & Tail likelihood ratio test
02 · Synthetic data

AI-generated data is Useful, not necessarily true.

90% of a biobank has no proteomic assay but complete genotypes and records. Rather than substituting predictions for data, I model them jointly inside a mixed model — AI model misspecification costs power, never validity.

Syn-PALM & MultiSynSurr
03 · Populations

Safely borrowing strength across heterogeneous populations.

A minority cohort is underpowered while a cohort a hundred times larger sits beside it. Pooling naively is worse than not borrowing at all; I decompose the target null instead of assuming transportability away.

HEART-GWAS
04 · Design

Decide how data can be collected.

Before anyone is enrolled, the design fixes how much a study will ever reveal. Covariate-adaptive randomization and design strategies for networked experiments help to get better treatment assignment.

Adaptive randomization & Network interference

“The auxiliary information is allowed to be arbitrarily wrong.”

This is the rule I hold myself to in my project. Validity — type I error, false discovery rate, unbiasedness for the target estimand — is established by derivation, never inherited from an assumption that the model, the borrowed population, or the imputation happens to be correct. Accuracy buys power, and nothing else. The result is a guarantee worth stating plainly: provably never worse than the classical analysis that throws the extra information away, and strictly better whenever that information is real.

Methodology

Inference with AI-generated Data Large-scale Composite-null Testing Cross-population Transfer Learning Covariate-adaptive Randomization Causal Inference under Interference

Applications

Genome-wide Association Studies Proteomics & pQTL Discovery Metabolomics & Nutritional Epidemiology Epigenome-wide Studies Population Biobanks Clinical Trials Networked & Economic Experiments
Where I'm headed

Over the next five years I want to build a general theory, and a usable software stack, for turning imperfect auxiliary information into valid scientific discovery — together with adversarial benchmarks, because this literature still has no shared standard for demonstrating that a method fails safely.

Mediation with AI-generated mediators

Exposures and outcomes are measured on everyone, the proteome and epigenome in between on almost no one. Calibrated synthetic mediators, tested with a synthetic tail likelihood ratio test, so that pathway discovery is no longer capped by assay budgets.

A unified theory of auxiliary evidence

A prediction model, another population, a historical control arm and an external registry are one formal object: decorrelate it from the target, decompose the null it can misrepresent, and decide how much to borrow decision-theoretically.

Foundation models as measurement instruments

Single-cell, protein-language and clinical models are becoming black-box, silently updated measurement devices. Conformal layers, drift diagnostics and selective-inference corrections give an end-to-end reliability audit for AI-assisted discovery.

05

Publications

* corresponding author; † co-first authors (equal contribution).

Book Chapters

  • Variable selection for missing data. Chapter in Modern Survey Analysis.
  • Statistical principles of data science. Chapter in Introduction to Data Science.
06

Software

Open-source R packages implementing my methods, and a data resource. Numbers refer to the publication list above.

Transfer learning with synthetic phenotype assisted linear mixed models for genetic discovery in under-represented populations.

Synthetic phenotype assisted linear mixed models for proteome-wide genetic discovery in incomplete biobank data.

Accompanies [12]

MultiSynSurr

Synthetic surrogate regression with several synthetic phenotypes kept as separate outcomes, for association studies of partially measured outcomes such as metabolites assayed in different sub-studies.

Accompanies [17]

Heterogeneity-aware empowerment via adaptive robust transfer.

Accompanies [16]

TLR

Tail likelihood ratio test for large-scale causal mediation under a composite null hypothesis.

Accompanies [1]

CARM

Covariate-adjusted adaptive randomization via Mahalanobis distance, including multi-arm trials.

Co-author · Accompanies [6] and [9]

SCR

Sequential covariate-adjusted randomization.

Accompanies [5]

Design of networked experiments via interference balancing.

Accompanies [2]

Genome-wide summary statistics for 2,916 plasma proteins in 402,086 UK Biobank participants.

Data resource · Accompanies [12]
07

Talks & Awards & Teaching & Service

Presentations
Nov. 2025; Mar. 2026; Aug. 2026
Robust synthetic data–assisted genome-wide association studies boost proteome-wide genetic discovery with partially observed data in biobanks
Statistical Genetics Meeting 2025; ILCCO Biostatistics Meeting 2026; JSM 2026 — Boston, USA
Aug. 2024
Tail likelihood ratio method for large-scale causal mediation hypothesis testing
Joint Statistical Meetings — Portland, USA
Jun. 2024
Causal mediation analysis for integrating exposure, genomic, and phenotype data
Statistical Genetics Meeting — Boston, USA
May 2024
Design strategies for networked experiments via interference balancing
The 37th New England Statistics Symposium — Connecticut, USA
Jun. 2021
Adaptive randomization via Mahalanobis distance
The Ph.D. Forum on Biostatistical Methods and Applications — Beijing, China
Awards and Honors
Jun. 2026Poster Award, 2026 ICSA Applied Statistics Symposium
Oct. 2022Top Ten Papers, 8th National Postgraduate Statistics Forum
Aug. 2021Top Ten Papers, 2nd Data Science and Modern Economic Statistics Forum
Dec. 2020First Prize, “BeiGene” Excellent Paper for Youth
Teaching and Mentoring
2021Teaching assistant, Renmin University of China — Probability Theory
2021Teaching assistant, Renmin University of China — Complex Statistical Analysis
2020Teaching assistant, Renmin University of China — Introduction to Data Science
CurrentResearch mentor to a Harvard College junior on an undergraduate research project
CurrentResearch mentor to a Ph.D. student in Professor Xihong Lin’s group
Professional Service
Journal referee: Statistica Sinica; Biostatistics; Journal of Data Science
08

Beyond the Data

Always in motion — on the water, on the court, on the snow. Away from the data, I'm happiest when my heart rate is up. I run marathons, play tennis, swim, and carve down ski slopes; I love the rhythm of rowing and the pull of a good race. And because the best moments are shared, I'm all in on team sports too — volleyball, dragon boat, and ultimate frisbee. Whatever the season, I'll keep moving.