I have fit a two-part model, where the first part is using a logistic regression to model the probability of seeing Y, and the second part is using a Gamma GLM regression with a log link to model the value of Y, conditional on it being positive.
I have then calculated predictions of Y for new values of X by multiplying the probability predicted from the logistic regression, by the value of Y predicted from the Gamma GLM regression for each value of X. How can I go about computing the prediction interval for specific values of X?
I was thinking of using bootstrapping, using the method suggested at the following link. However, I am not sure how I would bake in residual uncertainty over two models. https://stats.stackexchange.com/a/501275/360160