@mc-stan.org
Expressive probabilistic programming language for writing statistical models. Fast Bayesian inference. Interfaces for Python, Julia, R, and the Unix shell. A rich ecosystem of tools for validation and visualization. Home https://mc-stan.org/
🔥 Last Keynote for StanCon 2026 🔥
We are happy to present Mathew Kay (@mjskay.com) as a keynote at StanCon in Uppsala in August!
More information here:
discourse.mc-stan.org/t/announcing...
@mc-stan.org
my course notes on a bayesian workflow for (single agent) cognitive modeling are now fully revised and online: fusaroli.github.io/AdvancedCogn...
Predictive checks, updating checks, sensitivity analyses and simulation based calibration in @mc-stan.org
Feedback is very welcome!
Kalman filter. It still targets the correct posterior, but can be orders of magnitude more efficient for some widely used models. Other times it is just a little bit more efficient. Open-source Stan implementation (@mc-stan.org) will be on OSF in the afternoon. Preprint: doi.org/10.48550/arX...
Progress bar showing 2800/8000 35% ETA: 4m
Help to test new progress bar in CmdStanR by @josswright.bsky.social, see more at discourse.mc-stan.org/t/help-us-te...
A new blog post!
In which @matterofstats.bsky.social and I estimate our own risk preferences in @mc-stan.org with the hope of best responding to a proper scoring rule.
#EconSky #AFL
jamesblandecon.github.io/posts/2026-0...
Like usual, @mc-stan.org eats this stuff up. 7,000 observations, each with its own corresponding latent variable. Model estimated in a bit over 3 hours with no warnings.
Bayesian joint modelling using @mc-stan.org of wastewater and hospital admissions in the US led by @kaitejohnson9.bsky.social and others at the US CDC
Two days to StanCon 202 oral presentation abstract submission deadline!!!
🔥 StanCon 2026 third keynote announced 🔥
Kaitlyn Johnson,
London School of Hygiene & Tropical Medicine
More information here
discourse.mc-stan.org/t/announcing...
@mc-stan.org
25th February deadline is mainly for oral presentations, and poster submission deadline is 27th May. If you want to present a poster and need confirmation of acceptance earlier, you can submit a poster abstract now and get confirmation by March 25 as for oral presentations.
StanCon 2026 deadline for oral presentations 25th of February! discourse.mc-stan.org/t/stancon-20...
If you have any questions, ask in Stan discourse or contact one of the local organizing committee members
StanCon 20206 International Conferene on Bayesian Inference and Probabilistic Programming 17-21 August, 2026 Uppsala, Sweden
Three weeks time to submit contributed talk abstract to StanCon 2026! You can also submit a poster abstract early, if you need to make early travel plans. There will be travel and accommodation support for students, too!
More information about submitting at www.stancon2026.org/abstracts/
as I'm revising my course materials, I keep stumbling upon cool @mc-stan.org developments.
Current favorites:
1. your model has funnels and you exhausted reparametrization ideas: metric = "dense_e" makes your HMC learn about covariance btw parameters. Sloooow, but effective!
1/
wanna learn about cognitive modeling and love pizza? I am revising my cognitive modeling course notes and could use some feedback (or you might just enjoy learning about cog modeling in R and Stan): fusaroli.github.io/AdvancedCogn...
(only chapter 1-3 are in place, the others will come)
1/9 New blog is live! This is part 2 of a series—last time we looked at the Dunning-Kruger effect, now we are digging in to Implicit vs Explicit attitudes and the Implicit Association Test. To start, of course we need a good meme...
haines-lab.com/post/part-2-...
if you want to know how to compute marginal means from a mixed effects model in brms using rvars, then have I got a supplemental materials document for you pubs.asha.org/doi/10.1044/...
StanCon 2026 is this August 17-21 in Upsala, Sweden 🇸🇪
www.stancon2026.org
⏰ Abstracts for contributed talks are due Feb 25
⏰ Abstracts for posters are due May 27
And just to be clear: Yes, StanCon is my favorite conference to attend!! Can't wait for this one!
![R console output of the posterior summaries:
sumr |> arrange(ess_tail)
# A tibble: 3,986 × 4
variable rhat ess_bulk ess_tail
<chr> <dbl> <dbl> <dbl>
1 gamma[4,9] 1.02 153. 1861.
2 gamma[4,8] 1.02 191. 1921.
3 m[4] 1.02 211. 2336.
4 A[4,5] 1.01 440. 2918.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:udsm6acdtllf76voqzflv4ou/bafkreid5fwo76lqi7rhheijnnql6m4w3x5kvksbigjxf47uhapsh22zzrq)
R console output of the posterior summaries: sumr |> arrange(ess_tail) # A tibble: 3,986 × 4 variable rhat ess_bulk ess_tail <chr> <dbl> <dbl> <dbl> 1 gamma[4,9] 1.02 153. 1861. 2 gamma[4,8] 1.02 191. 1921. 3 m[4] 1.02 211. 2336. 4 A[4,5] 1.01 440. 2918.
Working on a fairly complex model and getting good tail-ESS but poor bulk-ESS values. Seems somewhat counterintuitive at first, but the model has multimodal posterior which likely explains this. @mc-stan.org #Bayesian #mcmc #stan #stats #rstats
StanCon 2026 tutorial and workshop deadlines in one week:
discourse.mc-stan.org/t/stancon-20...
@mc-stan.org
May 11, Short Course on Bayesian Causal Inference with Stan, Stress-Testing Assumptions: Bayesian Methods for Sensitivity Analysis in Causal Inference, in-person at the American Causal Inference Conference meeting in Salt Lake City. See more at discourse.mc-stan.org/t/upcoming-s...
February 5th in Bayesian Data Analysis Meetup virtual event:
Bayesian Models in Production by Ian Costley (Wegmans Food Markets)
...hands-on experience deploying Bayesian models built with Stan and PyMC into real production systems...
see more at discourse.mc-stan.org/t/feb-5th-ba...
Release of CmdStan 2.38
We are very happy to announce that the 2.38.0 release of CmdStan is now available on Github! As usual, the release of CmdStan is accompanied by new releases of Stan Math, core Stan, and Stanc3. This release cycle focused on stability and usability improvements, with a few…
🔥 Second Keynote for StanCon 2026 🔥
We present Fredrik Ronquist (Swedish Museum of Natural History) as the second keynote speaker
More information can be found here:
www.stancon2026.org/speakers/
🔥 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:
New projpred (projection predictive variable selection for brms and rstanarm) release 2.10.0. Frank Weber added support for censored observations when using the latent projection (see a vignette mc-stan.org/projpred/art...). @aloctavodia.bsky.social fixed bugs and made the release.
Seven-parameter drift-diffusion pdfs and cdfs now in Stan
statmodeling.stat.columbia.edu/2025/12/11/s...
A slew of improvements to NUTS
statmodeling.stat.columbia.edu/2025/12/11/a...
StanCon 2026 registration and abstract submission is now open!
Please spread the word!
discourse.mc-stan.org/t/stancon-20...
If you have a background in deploying Bayesian models at large or small scale for an organization and you would like to speak about it, please see this post by Brian Parbhu discourse.mc-stan.org/t/new-2025-2...
@bronder.deals's CppCon talk gives a nice overview of C++ implementation of Stan's autodiff