Dynamic Policyholder Behaviour (DPB) reflects the fact that a policyholder's propensity to exercise options available in a life insurance policy can be influenced by external factors. Recent industry developments mean that life insurance companies need to consider DPB in their modelling. During the second half of 2009, Milliman carried out a survey to analyse the extent to which European life insurance companies model DPB, for what purposes they use this modeling, the structure of these DPB models, and how they were derived.