The Tax Gradient: Spatial Aspects of Fiscal Competition
研究发现，州边界导致零售税负不连续，低税州一侧的地方税率会提高1.25个百分点，从而缩小州际税率差异；距离高税州边界越远，地方税率越低。
State borders create a discontinuous tax treatment of retail sales. In a Nash game, local tax rates will be higher on the low state tax side of a border. Local taxes will decrease from the nearest high-tax border and increase from the low-tax border. Using driving time from state borders and all local sales tax rates, local tax rates on the lowtax side of the border are 1.25 percentage points higher, reducing the differential in state tax rates by over three-quarters. A ten minute increase in driving time from the nearest high-tax state lowers a border town's local tax rate by 6 percent.