We have a zero-inflation×254 tag but no tag for hurdle models. I have just created hurdle-model×1. Now I am wondering if it should better be made a synonym of
[zero-inflation] or left alone as a separate tag.
According to What is the difference between zero-inflated and hurdle distributions (models)?, these two models are meaningfully distinct. However, most of the time they are supposed to deal with the same issue. It seems that the two models should better be assigned to a common "umbrella" tag. The question is: can
[zero-inflation] surve as such an umbrella tag DESPITE "zero-inflated model" and "hurdle model" being two different things? Can we perhaps view "zero inflation" as an umbrella name for the underlying issue?
The current wiki excerpt for
Variables that are counts (non-negative integers) often have an excess of zeroes compared to a certain count distribution. Zero-inflated regression models (e.g. zero inflated Poisson, zero inflated negative binomial) are designed to deal with this. Less commonly, continuous data can have this issue, and there is zero-inflated normal regression to deal with that situation.
If we make
[hurdle-model] a synonym, we could modify it e.g. like this:
Excess of zeroes in the data compared to a certain distribution that otherwise describes the data well. Regression approaches for count data include zero-inflated Poisson or negative binomial GLMs, and hurdle models.
Additional question: there also is a point-mass-at-zero×14 tag without an excerpt, that is probably supposed to be used for semi-continuous distributions with point mass at zero. I could write such an excerpt, but shouldn't we perhaps make it a synonym of
[zero-inflation] too? After all, a point mass at zero does yield "an excess of zeros" compared to any continuous distribution. And the current excerpt of
[zero-inflation] even mentions zero-inflated continuous models.