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Alex Luedtke

@alexluedtke.bsky.social
1.5K followers 240 following 24 posts

statistician • causal inference, machine learning, nonparametrics professor @harvardmed.bsky.social alexluedtke.com

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Reposted by Alex Luedtke
Lukasz Olejnik @lukaszolejnik.bsky.social · 14/04/2026
Physicist has written a fascinating big beautiful paper.Let’s not be afraid to call it what it is - groundbreaking. arxiv.org/abs/2603.21852
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Alex Luedtke @alexluedtke.bsky.social · 07/04/2026
Threatening genocide normalizes genocide.
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Reposted by Alex Luedtke
Lars van der Laan @larsvanderlaan3.bsky.social · 26/02/2026
🚨A Researcher's Guide to Empirical Risk Minimization I put together a guide on regret theory for empirical risk minimization (ERM) as I understand it. The goal was to compile results and proof techniques I’ve found useful in my own work. I hope people find it useful more broadly
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Reposted by Alex Luedtke
Rachel Leah Childers @donskerclass.bsky.social · 03/02/2026
Never have I felt more like my job will soon by taken by AI. Statistical learning theory in Lean: concentration inequalities, Dudley's entropy integral, and local Gaussian complexity bounds. 30000 lines of code, over 1000 lemmas, formalizing Wainwright and Boucheron et al arxiv.org/abs/2602.02285
Fig 4 from Zhang, Lee, Liu "Statistical Learning Theory in Lean 4: Empirical Processes from Scratch"
The dependency graph of the formalizations. Diagram shows proof of Dudley's entropy integral with preceding lemmas and Gaussian Lipschitz concentration likewise, feeding into a Gaussian Complexity inequality and an error bound for critical radius then used to prove sharp minimax error rates for linear regression.
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Reposted by Alex Luedtke
Paweł Morzywołek @pawelmorzywolek.bsky.social · 15/12/2025
New paper: Inference on Local Variable Importance Measures for Heterogeneous Treatment Effects (with Peter B. Gilbert & @alexluedtke.bsky.social). Preprint: arxiv.org/abs/2510.18843.
arxiv.org
Inference on Local Variable Importance Measures for Heterogeneous Treatment Effects
We provide an inferential framework to assess variable importance for heterogeneous treatment effects. This assessment is especially useful in high-risk domains such as medicine, where decision makers...
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Alex Luedtke @alexluedtke.bsky.social · 07/11/2025
I'm excited to dig into this new work on numerically approximating efficient influence functions. The main idea seems to be to use a Fourier-type approximation, rather than the kernel-smoother approximation used in earlier approaches. openreview.net/pdf/cfeab45d...
openreview.net
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Alex Luedtke @alexluedtke.bsky.social · 22/10/2025
📢 Postdoc opening in stats @harvardmed.bsky.social! Build variable-importance methods so patients know why a treatment is/isn't expected to work for them. Funding from PCORI (non-federal). Application review starts Dec 1. Details here: academicpositions.harvard.edu/postings/15365
academicpositions.harvard.edu
HMS - Postdoctoral Fellow in Health Care Policy - Statistical Methods
The Department of Health Care Policy at Harvard Medical School seeks a highly motivated postdoctoral fellow to join a PCORI-funded project developing new methods to improve the transparency of individ...
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Alex Luedtke @alexluedtke.bsky.social · 24/09/2025
New paper on generative modeling of counterfactual distributions! We give a way to answer "what if" questions with generative models. For example: what would faces look like if they were all smiling? arxiv.org/abs/2509.16842
Title page for paper:

DoubleGen: Debiased Generative Modeling of Counterfactuals

arXiv:2509.16842 (stat)

Alex Luedtke, Kenji FukumizuSelected attributes that are more common in smiling (n = 78 080) than in non-smiling (n = 84 690) CelebA faces. If a model is trained only on the smiling subset, it tends to over-produce these attributes instead of showing how the full population would look if everyone smiled.

Table:
            Lipstick   Makeup   Female*   Earrings   No-beard   Blonde
Smiling          56 %       47 %      65 %       26 %        88 %      18 %
Not smiling      38 %       30 %      52 %       12 %        79 %      12 %
Overall          47 %       38 %      58 %       19 %        83 %      15 %Counterfactual smiling celebrities generated by a traditional diffusion model trained on only smiling faces (top) and a DoubleGen diffusion model (bottom). Columns contain coupled samples, with the random seed set to the same value before generation. The stars mark the most qualitatively different pairs.

What’s visible: two horizontal rows, each showing twelve AI-generated smiling portraits.

Starred columns highlight the biggest shifts: in those pairs, DoubleGen produces faces with traits under-represented among smiling faces in the original data. Non-starred columns look nearly identical between the two rows.
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Reposted by Alex Luedtke
arxiv.stat.ME @arxiv-stat-me.bsky.social · 26/08/2025
Carlos Cinelli, Avi Feller, Guido Imbens, Edward Kennedy, Sara Magliacane, Jose Zubizarreta Challenges in Statistics: A Dozen Challenges in Causality and Causal Inference arxiv.org/abs/2508.17099
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Reposted by Alex Luedtke
Sam Power @spmontecarlo.bsky.social · 19/08/2025
I want to advertise some relatively recent work which I really like, and have been fortunate to play a small role in. The paper is titled "A New Proof of Sub-Gaussian Norm Concentration Inequality" (arxiv.org/abs/2503.14347), led by Zishun Liu and Yongxin Chen at Georgia Tech.
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Alex Luedtke @alexluedtke.bsky.social · 24/07/2025
Neat AI product for improving technical writing. Tried it on a 50 page draft of a causal ML paper. Of its top 10 comments, 4 concerned minor technical issues I'd missed (notation error, misapplication of definition, etc.). In my experience, vanilla chatbots wouldn't have caught these.
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Reposted by Alex Luedtke
Noah Greifer @noahgreifer.bsky.social · 04/06/2025
Starting to look like I might not be able to work at Harvard anymore due to recent funding cuts. If you know of any open statistical consulting positions that support remote work or are NYC-based, please reach out! 😅
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Alex Luedtke @alexluedtke.bsky.social · 23/05/2025
I've advised 15 PhD students—10 were international students. All graduates continue advancing U.S. excellence in research and education. Cutting off this pipeline of talent would be shortsighted.
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Reposted by Alex Luedtke
Bailey Bowcutt @baileybowcutt.bsky.social · 22/05/2025
I'm a current Harvard graduate student and I found out today that I had my NSF GRFP terminated without notification. I was awarded this individual research fellowship before even choosing Harvard as my graduate school
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Reposted by Alex Luedtke
Lars van der Laan @larsvanderlaan3.bsky.social · 19/05/2025
Had a great time presenting at #ACIC on doubly robust inference via calibration Calibrating nuisance estimates in DML protects against model misspecification and slow convergence. Just one line of code is all it takes.
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Alex Luedtke @alexluedtke.bsky.social · 30/04/2025
New paper, led by my student Alex Kokot! We study dataset compression through coreset selection - finding a small, weighted subset of observations that preserves information with respect to some divergence. arxiv.org/abs/2504.20194
The Sinkhorn reconstruction error in various dimensions (left) and dataset sizes (right). In the first plot the sample size is fixed at n=25,000, and for the latter the dimension is fixed at d=10. The proposed compression method, CO2, outperforms random sampling in all settings considered.Q-Q plots of the Sinkhorn reconstruction error (left) and l1 error between the label proportions (right) of the compressed data as compared to random samples. The proposed compression method, CO2, outperforms random sampling in all settings considered.
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Reposted by Alex Luedtke
Carl T. Bergstrom @carlbergstrom.com · 08/02/2025
The NIH overhead cut doesn't just hurt universities. It's deadly to the US economy. The US is a world leader in tech due to the ecosystem that NIH and NSF propel. It drives innovation for tech transfer, creates a highly-skilled sci/tech workforce, and fosters academic/industry crossfertilization.
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Lars van der Laan @larsvanderlaan3.bsky.social · 22/01/2025
Thrilled to share our new paper! We introduce a generalized autoDML framework for smooth functionals in general M-estimation problems, significantly broadening the scope of problems where automatic debiasing can be applied!
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Reposted by Alex Luedtke
Rachel Leah Childers @donskerclass.bsky.social · 31/12/2024
My traditional end-of-year review: some papers I read and liked in 2024. donskerclass.github.io/post/papers-...
donskerclass.github.io
Papers I Liked 2024 | David Childers
This has been another year where I felt like I slacked on my reading, and that probably is genuinely true for the tumultuous last half, but my read folder lists 154, so I can pick out a few that I lik...
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Alex Luedtke @alexluedtke.bsky.social · 24/11/2024
Welcome, @danielawitten.bsky.social!
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Reposted by Alex Luedtke
Edward H. Kennedy @edwardhkennedy.bsky.social · 22/11/2024
New paper! arxiv.org/pdf/2411.14285 Led by amazing postdoc Alex Levis: www.awlevis.com/about/ We show causal effects of new "soft" interventions are less sensitive to unmeasured confounding & study which effects are *least* sensitive to confounding -> makes new connections to optimal transport
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Alex Luedtke @alexluedtke.bsky.social · 12/11/2024
👋 In Tokyo this academic year, on sabbatical at the Institute of Statistical Mathematics. In town and interested in causal ML? Would love to grab coffee and chat.
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Reposted by Alex Luedtke
Adam L @adam-lg.bsky.social · 02/04/2024
"The Elements of Differentiable Programming" link: arxiv.org/abs/2403.14606 Basically: "autodiff - it's everywhere! what is it, and how do you use it?" seems like a good resource for anyone interested in data science, machine learning, "ai," neural nets, etc #blueskai #stats #mlsky
Artificial intelligence has recently experienced remarkable advances, fueled by large models, vast datasets, accelerated hardware, and, last but not least, the transformative power of differentiable programming. This new programming paradigm enables end-to-end differentiation of complex computer programs (including those with control flows and data structures), making gradient-based optimization of program parameters possible. As an emerging paradigm, differentiable programming builds upon several areas of computer science and applied mathematics, including automatic differentiation, graphical models, optimization and statistics. This book presents a comprehensive review of the fundamental concepts useful for differentiable programming. We adopt two main perspectives, that of optimization and that of probability, with clear analogies between the two.
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Alex Luedtke @alexluedtke.bsky.social · 09/10/2024
Do you know someone applying for a PhD in stat/biostat? Suggest they submit their draft application materials for feedback/mentoring! stat.uw.edu/pre-applicat...
stat.uw.edu
PARS | University of Washington Department of Statistics
The Department of Statistics at the University of Washington is launching the pre-application review service (PARS) initiative to provide support and mentorship to PhD applicants from historically marginalized groups.
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Alex Luedtke @alexluedtke.bsky.social · 25/06/2024
New paper! arxiv.org/abs/2405.08675 tldr: automatic differentiation can be used to derive efficient influence functions and construct efficient estimators.
algorithm returning estimandautomatic differentiation algorithmPython example, expected densityPython example, nonparametric R-squared
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