Measuring the Invisible: An Overview of and Outlook for Tax Non-Compliance Estimates and Measurement Methods for Switzerland

This paper gives an overview of tax non-compliance estimates and evaluates the suitability of various tax non-compliance measurement methods for Switzerland. The existing estimates for Switzerland focus strongly on non-declared assets and are based on a limited number of measurement methods. Nevertheless, the estimates range widely, between CHF 106 to over 500 billion for non-declared assets and 12.6 to 35.1 percent for income, for the time period 1970 to today. These estimates could be taken as a starting point for further tax non-compliance research. They should however be verified and supplemented by estimates resulting from other methods as a solid measurement of tax non-compliance requires a comprehensive approach including several methods. Further, the focus should shift from non-declared assets towards non-declared income.