Maths writer/cowritter needed: how you can't distinguish early exponential from early sigmoid

by Stuart Armstrong1 min read6th May 2020No comments


World Modeling

It's well known in FHI and similar circles, that it's impossible to distinguish an exponential (growth going up wildly) from a sigmoid/logistic curve (exponential growth until a turning point - an S shape) - until well after the turning point.

Which means we can't effectively predict that turning point. And so can't distinguish when a sigmoid will have a turning point, even when we know it must have one.

But this doesn't seem to exist in the statistics literature; and it would be very useful to have such a paper or textbook to point to.

We don't have time to write a full paper ourselves, but is there someone on this list with statistical experience who would like to write or co-write such a paper?

Since this result is important and as yet unpublished, it's plausible that such a publication may get an extremely high number of citations.