  Counting outcomes is the obvious algorithm for generating probabilities in
quantum mechanics without state-vector reduction (i.e. many-worlds). This
procedure has usually been rejected because for purely linear dynamics it gives
results in disagreement with experiment. Here it is shown that if non-linear
decoherence effects (previously proposed by other authors) are combined with an
exponential time dependence of the scale for the non-linear effects, the
correct measure-dependent probabilities can emerge via outcome counting,
without the addition of any stochastic fields or metaphysical hypotheses.
