A method is presented to analyze and observe, in molecular dynamic simulations, the statistical properties of instantaneous cluster transitions, mainly fusions and fissions for a homogeneous vapor at equilibrium. The method yields the way to obtain mean lives, branching ratios and, to some extent, transition rates as well. To the best of our knowledge branching rations in cluster decays have not been measured before (simulationally or experimentally). An application of this method to a model system provides a critical reassessment of the standard Homogeneous Nucleation Theory (HNT). Our own simulations show that transitions different from absorbing or evaporating a monomer are quite important, representing in some cases 50% of all decay events. Our method also shows unequivocally that the decay processes involving clusters classified by size alone are not Markovian.