> The amount of data needed to tell between ... two power-law distributions, >trillion. I don't agree with this as a statement of fact (except in the obvious

> The amount of data needed to tell between ... two power-law distributions, >trillion. I don't agree with this as a statement of fact (except in the obvious case of two power-law distributions with extremely close parameters). Supposing it was true, that would mean that you would almost never have to actually worry about the parameter, because unless your dataset is that large one power law is about as good as any other for describing your data.