SALT Report 3928 – A study released in March 2017, by the National Conference of State Legislatures and the International Council of Shopping Centers, quantifies the uncollected state and local sales taxes resulting from electronic commerce. A subsequent study expands the analysis to include an estimation of the sales tax loss from non-electronic remote sales. The study utilizes information from a 2009 study conducted by three University of Tennessee professors and the subsequent analysis by the Washington State Office of Financial Management.
In 2012 the estimated uncollected sales and use taxes across the US was $23 billion. In 2015 the estimate rose to $29 billion.