This paper reports on a study designed to improve the information on income flows and income distribution in the Netherlands national accounts by building a bridge between the national accounts and income tax statistics. The methods used are described in some detail, and the significance of the results obtained is discussed. The figures show rather substantial fluctuations in the share of proprietors relative to that of wage earners. This result is not unexpected, since the share of proprietors is much more sensitive to the level of economic activity, but it does limit the usefulness of the figures for short-run economic policy determination. In the longer run, however, they do show what the development of the average incomes of the various social groups has been, and to what extent government action has contributed to that development.