Skip to content

BDA FREE (Bayesian Data Analysis now available online as pdf)

Our book, Bayesian Data Analysis, is now available for download for non-commercial purposes!

You can find the link here, along with lots more stuff, including:

• Aki Vehtari’s course material, including video lectures, slides, and his notes for most of the chapters

• 77 best lines from my course

• Data and code

• Solutions to some of the exercises

We started writing this book in 1991, the first edition came out in 1995, now we’re on the third edition . . . it’s been a long time.

If you want the hard copy (which I still prefer, as I can flip through it without disturbing whatever is on my screen), you can still buy it at a reasonable price.


  1. W00T! This is great news. I strongly prefer pdfs because they fit on my iPad and are searchable. The iPad changed my reading life, especially after they improved resolution so that subscripts and even double subscripts are readable.

    P.S. My first edition copy had something lik 64 pages upside down and backwards! Since it wasn’t as valuable as an inverted Jenny, I recycled it when the second edition came out, a fate eventually shared by the second edition copy that replaced it. Can’t wait to throw BDA3 into the chipper when BDA4 comes out.

    • WOOT! from me as well. I’m glad it wasn’t released as a crappy ePub or mobi with regular text and horrific tiny jpgs of equations and symbols.

      When are we going to get MathJax in ebooks?

    • Andrew says:


      You get a lot of credit for this pdf release. The immediate motivation was when we were working on our Bayesian Workflow book last year and I wrote a chapter talking about BDA3. You said you didn’t want our book to refer to anything that wasn’t free, so I started the process resulting in getting permission to post the pdf. Rob Calver, our editor at CRC Press, also gets credit for being cool with it.

      • Zad says:

        Andrew, is this Bayesian workflow book for the public or internal use?

      • Phil says:

        This is fantastic. I can’t count how many people I’ve sent the ‘8 schools’ example to, in the form of screenshots. Well, that’s not true, I can count them: there are four. Still, you get the idea.

        Big big thanks to Rob Calver and CRC press, and to everyone else who is presumably going to get fewer dollars this way. If you implement a way for people to donate to reward the authors and the press, I, for one, will contribute. Not a heckuva lot, but something!

  2. Bruce McCullough says:

    There’s some hilarious gold in the “77 best lines from my course”, e.g.,

    1. “God created the world in 7 days and we haven’t seen much of him since.”
    (God draws θ from an urn and then is out of the picture)

    17. “As you know from teaching introductory statistics, 30 is infinity.”

    Read the rest for yourself.

  3. walter says:

    Great addition to my printed copy

  4. Esad Mumdzic says:

    what else to say but Thank You!

  5. Tom says:

    I bought it in the summer, and skimmed through it but it is still sitting on my shelf though as I have not had time to get to it fully. There is so much frequentist “infrastructure” around me (both in my field, as bayesian is not common, and in my teaching that has somehow to follow the old hypothesis testing framework) that I am afraid it will take me a while. Nice to make it free though, thanks.

  6. Brandon says:

    Amazing, thank you so much!

  7. Christopher Blanchard says:

    Brilliant. I’m trying to re-learn some statistics, with more sense mixed in than there was in my first degree – that was economics (“Political Economy”, from Glasgow, many years ago), and by the time I got the thing I didn’t believe most of it. Reasons included the way in which economics papers would cite the central limit theorem (all the time – back then), when what was really happening was that a rubbish sampling procedure can leave any distribution looking normal, if I have understood this properly. That was only noddy statistics, even if the courses were labeled econometrics. Lots of other problems, including economists fundamentally not understanding either markets or money systems, which are kind of fundamental to the discipline, but your strictures on psychology, particularly, read very well or, at least, match my life-long predjudices. This book should help a lot.

Leave a Reply