How to truncate a multivariate normal distribution? (sidebar, how to access old stan mailing lists posts?)

Hello! I am attempting to build a dynamic linear model where the coefficients are constrained to be above 0 for domain-specific reasons. I would like to model the covariance between the coefficients (e.g. if one goes up, does that make another more likely to increase? decrease?)

Stan does not allow the truncation of multivariate distributions. However, it seems that I am not the first person that has asked this question

But when I click on that link I get the following warning:

I am curious if (a) anyone has any thoughts for how to model a truncated multivariate normal distribution in this context or (b) can open up access to the old mailing list conversations (I swear I could access them before!)


Wow, thank you @bgoodri! And so quick! Much appreciated.

In days where google archives anything I wished the old Stan google group could be held accessible.
It’s a great source of information.