>>To be more precise, the proposed model is a gamma density kernel, not
a
bonafide gamma density ,which integrates on 1. Of course in this
context, the function is used to model nonlinear trend, not a
probability distribution of some random variable.>>
Right, and thus it's not dissimilar from using the logistic CDF as a
model for growth between asymptotes, which is often done using, say,
Gaussian errors around the curve itself.
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