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0 votes
1 answer
32 views

How to choose between gamma and Gaussian given a choice of gauges?

I'm trying to make the choice between the gamma and Gaussian distributions as a prior distribution for some data. When I learned statistics a while ago, I was given the rule of thumb: if your data ...
Corbin's user avatar
  • 111
0 votes
0 answers
103 views

posterior predictive of a normal distribution with normal prior over mean and Gamma prior over precision

What is the posterior predictive of a normal distribution with normal prior over mean and Gamma prior over precision. Thus, what is the distribution of x given: \begin{equation} x \sim \mathcal{N}(x; \...
Snowy Baboon's user avatar
0 votes
1 answer
57 views

Eliciting a Gamma informative prior in a Gamma–Poisson Bayesian problem

I employ the Gamma–Poisson conjugate family for my statistical model. I want to use an informative prior. From theory, I know that the values of the Gamma-distributed random variable lie within the ...
Valerio's user avatar
  • 37
1 vote
1 answer
336 views

How can I find the posterior distribution for gammadistributed data and prior?

I am working on a project where I believe Bayesian statistics should be useful. However, my knowledge about Bayesian statistics are very scarce. Suppose I got data following a Gamma distribution with ...
alaj1716's user avatar
1 vote
1 answer
206 views

The PDF of the Data (Marginal Likelihood) Given the Prior of a Gamma Distribution with Prior on the $ \beta $ Paraneter

Given a model where $ x_i | \beta \sim \mathcal{Gamma} ( \alpha, \beta ) $ where $ \beta \sim \mathcal{Gamma} ( \alpha0, \beta0 ) $, is there a closed form formula for the PDF of $ x_i $? Namely, what'...
David's user avatar
  • 145
2 votes
0 answers
1k views

Choosing priors for the parameters of Gamma distribution

Suppose that $X_1, X_2, \cdots, X_n$ is a sample drawn from a Gamma distribution with parameter $\alpha$ and $\beta$. Then, the likelihood function can be written as follows: \begin{equation} L(\...
Statistics 's user avatar
4 votes
1 answer
451 views

Showing $X\sim \operatorname{Poi}(\lambda)$ is minimax

Assume that $X$ has $\operatorname{Poisson} (\lambda)$ distribution and the loss function is $\ell(\lambda,a)=\frac{(\lambda-a)^2}{\lambda}$. Now, I want to show that $X$ is minimax. A hint that is ...
statwoman's user avatar
  • 703
1 vote
0 answers
3k views

How does one place an uninformative prior on a Gamma Distribution?

I'd like to choose an uninformative prior for the scale and shape parameters of the Gamma distribution. Any help and suggestions will be appreciated.
desert_ranger's user avatar
3 votes
1 answer
107 views

How to calculate the posterior distribution from the density

I'm stuck on a answer from an old exam. The task is to use a Poisson distribution and a Gamma distribution as prior to calculate the posterior density: $$ p(\lambda|x) \propto L(\lambda)p(\lambda)\...
david576's user avatar
  • 113
0 votes
0 answers
22 views

What is the distribution of a r.v. if the reciprocal is distributed gamma?

I want to find the posterior distribution of σ^2 when (X1, X2, ..., Xn) ~ N(μ,σ^2), μ is known, and 1/(σ^2) ~ Gamma(α,β), but I'm not sure how to find the prior of σ^2 given the prior of 1/(σ^2). ...
Nats24's user avatar
  • 11
3 votes
0 answers
317 views

How do I choose a prior for this hierarchical model? (Kruschke book)

I am working through Kruschke's "Doing Bayesian Data Analysis", currently working on the Hierarchical models chapter. The book uses JAGS for MCMC. One of the exercises asks the reader to compare two ...
Mike Fenning's user avatar
1 vote
1 answer
460 views

Deriving Marginal Distribution of Poisson [duplicate]

How do you find the marginal distribution of a Poisson distribution given a gamma(a,b) prior?
new2stats's user avatar
3 votes
1 answer
5k views

Show posterior mean can be written as a weighted average of the prior mean and MLE

Suppose $Y_1, \dots Y_n$ are exponentially distributed: $Y_i | \lambda \sim Exp(\lambda)$. Find the conjugate prior for $\lambda$, and the corresponding posterior distribution. Show that the posterior ...
fhaney's user avatar
  • 53
2 votes
1 answer
261 views

Strange behavior of Gamma prior in a setting with binomial likelihood

I am trying to use Bayes theorem to estimate the probability of a binary event. To give a (simplified) example: Let's say our a priori guess of the probability of the event per trial is 0.3 (and the ...
LuckyPal's user avatar
  • 1,900
1 vote
0 answers
397 views

Gamma-2 Distribution in Bayesian

According to the material I have in hand for Bayesian Econometrics, we define the pdf of a Gamma-2 distributed random variable $Z$ with parameter $\mu > 0$ and degrees of freedom $\nu > 0 $, ...
adrian1121's user avatar
  • 1,116

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