ABSTRACT
Let X 1, X 2,… be exchangeable random variables. By de Finetti’s Theorem, there exists a prior II such that P ̴ Π and given P, X 1, X 2, … are i.i.d. P. We give necessary and sufficient conditions for Π to be (a) tailfree and (b) neutral to the right. En route to such characterization we also obtain characterizations in terms of the posterior.
