Aki Vehtari
avehtari.bsky.social
Aki Vehtari
@avehtari.bsky.social
Academy Professor in computational Bayesian modeling at Aalto University, Finland. Bayesian Data Analysis 3rd ed, Regression and Other Stories, and Active Statistics co-author. #mcmc_stan and #arviz developer.

Web page https://users.aalto.fi/~ave/
Pinned
All three books I've co-authored are freely available online for non-commercial use:

- #Bayesian Data Analysis, 3rd ed (aka BDA3) at stat.columbia.edu/~gelman/book/

- #Regression and Other Stories at avehtari.github.io/ROS-Examples/

- Active Statistics at avehtari.github.io/ActiveStatis...
Reposted by Aki Vehtari
Statistical Rethinking 2026 Lecture B01 Multilevel Models is online. This is the first lecture of the "experienced" section, in which we start with multilevel models and venture into vast covariance spaces. Full lecture list still here: github.com/rmcelreath/s...
Statistical Rethinking 2026 - Lecture B01 - Multilevel Models
YouTube video by Richard McElreath
www.youtube.com
January 9, 2026 at 10:34 AM
Reposted by Aki Vehtari
Hey, that's my package! 🖤💙 #bpvars #bsvars #rstats
New on CRAN: bpvars (1.0). View at https://CRAN.R-project.org/package=bpvars
bpvars: Forecasting with Bayesian Panel Vector Autoregressions
Provides Bayesian estimation and forecasting of dynamic panel data using Bayesian Panel Vector Autoregressions with hierarchical prior distributions. The models include country-specific VARs that share a global prior distribution that extend the model by Jarociński (2010) &lt;<a href="https://doi.org/10.1002%2Fjae.1082" target="_top">doi:10.1002/jae.1082</a>&gt;. Under this prior expected value, each country's system follows a global VAR with country-invariant parameters. Further flexibility is provided by the hierarchical prior structure that retains the Minnesota prior interpretation for the global VAR and features estimated prior covariance matrices, shrinkage, and persistence levels. Bayesian forecasting is developed for models including exogenous variables, allowing conditional forecasts given the future trajectories of some variables and restricted forecasts assuring that rates are forecasted to stay positive and less than 100. The package implements the model specification, estimation, and forecasting routines, facilitating coherent workflows and reproducibility. It also includes automated pseudo-out-of-sample forecasting and computation of forecasting performance measures. Beautiful plots, informative summary functions, and extensive documentation complement all this. An extraordinary computational speed is achieved thanks to employing frontier econometric and numerical techniques and algorithms written in 'C++'. The 'bpvars' package is aligned regarding objects, workflows, and code structure with the 'R' packages 'bsvars' by Woźniak (2024) &lt;<a href="https://doi.org/10.32614%2FCRAN.package.bsvars" target="_top">doi:10.32614/CRAN.package.bsvars</a>&gt; and 'bsvarSIGNs' by Wang &amp; Woźniak (2025) &lt;<a href="https://doi.org/10.32614%2FCRAN.package.bsvarSIGNs" target="_top">doi:10.32614/CRAN.package.bsvarSIGNs</a>&gt;, and they constitute an integrated toolset. Copyright: 2025 International Labour Organization.
CRAN.R-project.org
December 13, 2025 at 9:16 AM
My dept has an open assistant professor position (DL 2nd Feb). Although the call indicates special interest in datacenter-scale computing systems research, any research area is applicable and this would be a great place also for someone doing Bayesian flavored research

www.aalto.fi/en/open-posi...
Assistant Professor in Computer Science | Aalto University
Candidates applying to this call are considered for Assistant Professor position only. Applicants are required to have a doctoral degree and a publication track record in top journals and conferences in a relevant field.
www.aalto.fi
January 7, 2026 at 8:12 AM
PI positions at ELLIS Institute Finland. DL 12th Jan. These include professor position (tenure track, different levels) affiliated in a Finnish university. See universities and preferred research areas at www.ellisinstitute.fi/PI-recruit-2...

Some of these would be good for Bayesian flavored PIs!
Principal Investigator positions at ELLIS Institute Finland | ELLIS Institute Finland
Call for new PIs in artificial intelligence and machine learning
www.ellisinstitute.fi
January 7, 2026 at 8:03 AM
During the last few weeks, Jonah Gabry and I have been reviewing and improving more than 14k lines of code for the Bayesian Workflow book. Still some things to fix, but soon ready
We're doing the final sprint, and I think we're able to send the PDF of the forthcoming Bayesian Workflow book to the publisher in the next two weeks (500+ pages), which would mean it would be published some time next year
January 7, 2026 at 7:50 AM
Reposted by Aki Vehtari
And we're live, Lecture A1 is online. Introduction to Bayesian workflow, generative models, estimands, estimators, estimates, error checking, beginnings of probability theory and Bayesian updating. www.youtube.com/watch?v=ztbY...
January 6, 2026 at 11:02 AM
Sunshine, smoking ice and ice flowers along our walk today (photos by my wife)
January 5, 2026 at 4:46 PM
Reposted by Aki Vehtari
The courses for SISMID 2026 are now online: sismid.sph.emory.edu/modules/inde...

I really enjoyed teaching nowcasting and forecasting with Nick Reich last year. This year, we have split the course into two linked courses: first delays, Rt, and nowcasting, and then short-term forecasting.
In-Person Program
sismid.sph.emory.edu
January 5, 2026 at 2:51 PM
Reposted by Aki Vehtari
The 1.3.0 version of my {brms} + {tidyverse} translation of Kruschke's "Doing Bayesian data analysis" is up!

solomon.quarto.pub/dbda2

#rstats

1/8
Doing Bayesian Data Analysis in brms and the tidyverse
solomon.quarto.pub
January 2, 2026 at 5:00 PM
Reposted by Aki Vehtari
This one is a foundational one: #ExperimentalTrialDesign the ̶r̶i̶g̶h̶t̶ Bayesian way, with no other than Scott Berry, from Berry Consultants, LLC!

Enjoy, and happy new year, my dear Bayesians 🖖
Clinical trials don’t fail because patients fail.
They fail when designs stop learning.

Episode 148 of Learning Bayesian Statistics explores adaptive & platform trials and why "wait for the final analysis" isn’t neutral in ALS or pandemics.

🔗 learnbayesstats.com/episode/148-...

#newEpisode #bayes
January 2, 2026 at 11:16 AM
Reposted by Aki Vehtari
Some lecture notes on spatial and temporal modelling, illustrated using R - darrenjw.github.io/spatio-tempo... - #rstats #rspatial #quarto
Spatial and temporal statistics
darrenjw.github.io
January 1, 2026 at 12:31 PM
Reposted by Aki Vehtari
🔥 First Keynote and Program committe for StanCon 2026 🔥

We present Anna Dreber (Stockholm School of Economics) as the first keynote speaker

More information can be found here:
Announcing StanCon 2026 First Keynote and Program Committee
StanCon 2026 will take place 17–21 August 2026 in Uppsala, Sweden - details at https://stancon2026.org First Keynote Confirmed Speaker Anna Dreber (Stockholm School of Economics) (Predicting) replic...
discourse.mc-stan.org
December 22, 2025 at 8:34 AM
Reposted by Aki Vehtari
ELLIS Institute Finland offers:
🎓 Professorship affiliation at partner university in 🇫🇮
💻 Access to world-class computing infrastructure @lumi-supercomputer.eu
🧠 Europe's best AI + machine learning researchers as colleagues in the @ellis.eu network.
Join us! www.ellisinstitute.fi/PI-recruit-2...
December 19, 2025 at 9:07 AM
Reposted by Aki Vehtari
Just gave my last talk of the year!

2025 was quite packed, I gave talks about:
- the age-period-cohort problem
- making rigorous causal inference more mainstream
- mediation analysis
- marginaleffects
- causal graphs (x10)

If you're curious, check out my slides here: juliarohrer.com/resources/
Resources
Here you can find a collection of things that may be helpful, including slide decks, a curated list of introductory papers and blog posts, as well as some infographics I have generated to explain v…
juliarohrer.com
December 18, 2025 at 12:38 PM
Reposted by Aki Vehtari
The Max Planck Society has begun an exploratory round table for open science. We are drafting some recommendations to leadership. Still a long way to go! But here are my notes on the most recent draft, just so you all know how I am trying to steer things.
December 17, 2025 at 11:33 AM
Reposted by Aki Vehtari
We are hiring an Assistant Professor in computer science! This is a broad call, all areas of computer science will be considered! We are in particular interested in datacenter-scale computing systems.
www.aalto.fi/en/open-posi...
Assistant Professor in Computer Science | Aalto University
Candidates applying to this call are considered for Assistant Professor position only. Applicants are required to have a doctoral degree and a publication track record in top journals and conferences in a relevant field.
www.aalto.fi
December 17, 2025 at 1:43 PM
We're doing the final sprint, and I think we're able to send the PDF of the forthcoming Bayesian Workflow book to the publisher in the next two weeks (500+ pages), which would mean it would be published some time next year
December 16, 2025 at 5:21 PM
Reposted by Aki Vehtari
CVCT 2025 and Bayesian Model Guiding Iterative, Personalized Anticoagulant Dosing Decision-Making www.generable.com/post/cvct-2025
CVCT 2025 and Bayesian Model Guiding Iterative, Personalized Anticoagulant Dosing Decision-Making | Eric Novik | Generable
ENGAGE AF-TIMI 48 Trial Reanalysis
www.generable.com
December 15, 2025 at 7:38 PM
Reposted by Aki Vehtari
1 month until deadline! Join us to build your own lab in AI + machine learning research. World-class resources incl. @lumi-supercomputer.eu, generous starting package & professorship affiliation with a university in the world’s happiest country! ➡️ www.ellisinstitute.fi/PI-recruit-2...
#hiring
December 12, 2025 at 12:11 PM
Reposted by Aki Vehtari
Putting together a weekly book club for "Regression and Other Stories" (reply if interested!) and this page, "Common statistical tests are linear models," is a key motivation. If you git gud at regression, so much else comes along for free.
lindeloev.github.io/tests-as-lin...

#statsky
Common statistical tests are linear models (or: how to teach stats)
lindeloev.github.io
December 11, 2025 at 9:17 PM
Reposted by Aki Vehtari
Reposted by Aki Vehtari
Seven-parameter drift-diffusion pdfs and cdfs now in Stan
statmodeling.stat.columbia.edu/2025/12/11/s...
Seven-parameter drift-diffusion pdfs and cdfs now in Stan | Statistical Modeling, Causal Inference, and Social Science
statmodeling.stat.columbia.edu
December 11, 2025 at 9:00 PM
All the material for my Bayesian Data Analysis course is available online, including the lectures, which we re-recorded this fall (some of them by @aloctavodia.bsky.social and Noa Kallioinen while I was on vacation). The video links are listed in the schedule at avehtari.github.io/BDA_course_A...
Bayesian Data Analysis course - Aalto 2025 – Bayesian Data Analysis course
avehtari.github.io
December 11, 2025 at 2:20 PM
Reposted by Aki Vehtari
🔥 StanCon 2026 registration and abstract submission are now open! 🔥

Please spread the word!

discourse.mc-stan.org/t/stancon-20...
StanCon 2026 registration and abstract submission is now open
Hi everyone! Registration for StanCon 2026 in Uppsala, Sweden, is now open! You can already register and submit abstracts for contributions. Our first keynote speaker will be announced soon. New thi...
discourse.mc-stan.org
December 11, 2025 at 12:58 PM
A nice set of examples illustrating "Complementary strengths of the Neyman-Rubin and graphical causal frameworks"
Tetiana Gorbach, Xavier de Luna, Juha Karvanen, Ingeborg Waernbaum
Complementary strengths of the Neyman-Rubin and graphical causal frameworks
https://arxiv.org/abs/2512.09130
December 11, 2025 at 11:55 AM