check_zeroinflation: Check for zero-inflation in count models
Description
check_zeroinflation() checks whether count models are
over- or underfitting zeros in the outcome.
Usage
check_zeroinflation(x, tolerance = 0.05)
Value
A list with information about the amount of predicted and observed
zeros in the outcome, as well as the ratio between these two values.
Arguments
x
Fitted model of class merMod, glmmTMB, glm,
or glm.nb (package MASS).
tolerance
The tolerance for the ratio of observed and predicted
zeros to considered as over- or underfitting zeros. A ratio
between 1 +/- tolerance is considered as OK, while a ratio
beyond or below this threshold would indicate over- or underfitting.
Details
If the amount of observed zeros is larger than the amount of
predicted zeros, the model is underfitting zeros, which indicates a
zero-inflation in the data. In such cases, it is recommended to use
negative binomial or zero-inflated models.