Social networks and tax avoidance: evidence from a well-defined Norwegian tax shelter

In 2005, over 8% of Norwegian shareholders transferred their shares to new (legal) tax shelters intended to defer taxation of capital gains and dividends that would otherwise be taxable in the aftermath of a reform implemented in 2006. Using detailed administrative data, we identify family networks and describe how take-up of tax avoidance progresses within a network. A feature of the reform was that the eligibility to set up a tax shelter changed discontinuously with individual shareholding of a firm and we use this fact to estimate the causal effect of availability of tax avoidance for a taxpayer on tax avoidance by others in the network. We find that eligibility in a social network increases the likelihood that others will take-up. This suggests that taxpayers affect each other's decisions about tax avoidance, highlighting the importance of accounting for social interactions in understanding enforcement and tax avoidance behavior, and providing a concrete example of optimization frictions in the context of behavioral responses to taxation.