Combining theoretical and practical aspects of policy analysis, this book evaluates actual and proposed policy reforms to income tax and transfer systems, using a behavioural tax microsimulation model. It highlights how these models allow for the full details of tax systems and the considerable population heterogeneity that is found in practice. John Creedy and Penny Mok look at how such models can be used to obtain summary measures that are relevant in tax debates. These include elasticities of labour supply and measures of the welfare effects of tax changes, in terms of excess burdens. Chapters further examine how models can be used to search systematically, across a range of policy changes, for revenue-neutral reforms which result in an improvement, in terms of an explicit evaluation function. This will be a timely read for students of public finance, welfare and labour economics. The careful attention paid to metrics used in policy evaluations will also make this a useful book for researchers and policy advisors concerned with income taxation, social transfers, inequality and poverty measurement.