B ayesian Claims Reserving

Abstract

Claims reserving methods are usually classified as stochastic or nonstochastic (deterministic) depending on whether or not they allow for random variation. Bayesian methods fall within the first class. Being stochastic, they allow the actuary to carry out statistical inference of reserve estimates as opposed to deterministic models, like the traditional chain‐ladder. As an inference process, the Bayesian approach is an alternative to classical or frequentist statistical inference. From a theoretical point of view, Bayesian methods have an axiomatic foundation and are derived from first principles. From a practical perspective, Bayesian inference is the process of fitting a probability model to a set of data and summarizing the result by a probability distribution on the parameters of the model and on unobserved quantities, such as predictions for new observations.