Tax and Welfare Analysis (TAWA) Commissioning Manual

Tax and Welfare Analysis (TAWA) is the Treasury’s microsimulation model of the New Zealand personal tax and transfer system. It applies potential policy changes to individuals in its input data, and then scales up and aggregates the results so that they are representative of the New Zealand population. It is used extensively within Treasury and in external work related to policy analysis of tax and welfare settings.

This guidance document sets out the standard steps in the commissioning process, quality assurance practices, guidance on assessing and communicating the reliability of estimates, disclosure and associated modelling caveats. This information is intended as a resource to clarify expectations for all parties involved in this process.