As we explain below, there are three major reasons for the differences between our estimates and those of the Fox Study: First, the Fox Study substantially overstates un-collected taxes associated with business to- business (B2B) online sales; second, the Fox Study un-derstates tax collections by small firms; third, with respect to “out-year” projections, the Fox Study assumes what we regard as an un-realistically high and un-sustainable growth rate for online sales, especially considering the fact that the growth of broadband penetration among U.S. households – one of the primary drivers of online sales growth – is slowing as household broadband penetration approaches saturation.