Mark Rieke
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markjrieke.bsky.social
Mark Rieke
@markjrieke.bsky.social
certified big nerd | big #rstats dweeb | accidental python fan | he/him
thedatadiary.net
Reposted by Mark Rieke
Also, Yglesias lecturing people on uncertainty when it comes to interpreting polling data is laughable
February 15, 2026 at 5:11 PM
Reposted by Mark Rieke
Or, as written up in SIGBOIVK last year:
February 15, 2026 at 3:42 PM
I have concluded that the gamma distribution has too many parameterizations and simply needs to chill, thank you
February 13, 2026 at 5:32 PM
we have a slightly different formulation at work that gets around this --- I'll ping you on slack when I get online !
February 13, 2026 at 12:57 PM
ooh! no, wasn't aware --- aside from the super simple sufficient forms (binomial & counts of poisson obs), I haven't done too much w/sufficiency (I've implemented a sufficient normal like one time remember it being a struggle lol)
February 13, 2026 at 4:32 AM
oh yeah that's why my gut says that sum(x) ~ Gamma(n * alpha, theta) isn't a sufficient stat.

Link here shows what I get if I just repeatedly multiply the gamma pdf given new elements of x. Need to double check but it feels like this might actually give sufficiency?

bsky.app/profile/mark...
if I just sit down and bake out what a repeated product of the gamma pdf is I end up with this --- needs to be checked with simulation, but certainly passes the gut check
February 13, 2026 at 4:18 AM
I haven't yet simulated, but IIRC my thinking was that by summarizing (x1, x2, ... xn) to sum(x), you lose some information in that there are many combinations of alpha/theta that can reasonably be fit to a single observation of sum(x)
February 13, 2026 at 4:07 AM
oops xprod and xsum should index n here (xprod[n] & xsum[n])
February 12, 2026 at 10:29 PM
moreso scary in the sense that I've got ptsd from thinking the sufficient normal was straightforward then banging my head against a wall until I got a working solution lol

(the sufficient normal was also my crash course in "sometimes the centered parameterization samples better")
February 12, 2026 at 10:03 PM
point estimate probability says 100% chance of bayesian takeover 😈
February 12, 2026 at 4:02 PM