Structural models, derived from economic theory and embedded directly in an econometric framework, will be estimated on Norwegian longitudinal household data. The estimated models will be used to evaluate changes in tax systems and tax reforms. In particu lar we will study the effects of tax reforms on labor supply (participation and hours worked as well as on the choice of sector), and portfolio choices and savings in households. We will distinguish between public and private sectors, and self-employment. A new issue in this type of analysis will be the assessment of the impact of tax rule changes on mobility in the labor market. Because all details of the tax systems are used in the analysis we are able to evaluate the impacts of labor income taxes and c apital taxes on household behavior. In reporting the results we will show how households in different deciles of the household disposable income distribution are affected. We will report the gain and loss in utility terms and the evolution in these gains and losses for households in the period studied (1986-200x, where x is the latest year for which we have observations).