Microsimulation models provide an exciting new tool for analysing the distributional impact and cost of government policy changes. They can also be used to analyse the current or future structure of society. This volume contains papers describing new developments at the frontiers of microsimulation modelling, and draws upon experiences in a wide range of countries. Some papers aim to share with other modellers, experience gained in designing and running microsimulation models and their use in government policy formulation. They also examine issues at the frontiers of the discipline, such as how to include usage of health, education and welfare services in models. Other chapters focus upon describing the innovative new approaches being taken in dynamic microsimulation modelling. They describe some of the policy applications for which dynamic models are being used in Europe, Australia and New Zealand. Topics covered include retirement income modelling, pension reform, the behavioural impact of tax changes, child care demand, and the inclusion of government services within models. Attention is also given to validating the results of models and estimating their statistical reliability.