Per capita retail sales therefore represents the average level of taxable retail sales for all residents in an area. The county ratios of 1998 per capita taxable sales to 1998 per capita personal income were compared to the same ratio for the state. The county statistics were then indexed to the state ratio in order to measure the relative gain or loss of potential taxable sales dollars. An index greater than the state value of 1.00 indicated the ability to exceed potential taxable retail sales. Areas with an index above 1. 00 receive more taxable sales dollars for each dollar of per capita personal income than those areas with an index less than 1.00.
Various factors contribute to a county's ability to exceed their retail sales potential.
Some of the counties serve as a regional trade center for their area, drawing shoppers from surrounding counties. Another commonality for counties with high retail sales potential is the existence of hospitals and regional medical centers that help many of these areas gain taxable sales. For many, a trip to the doctor may also involve travel, dining out and some shopping. Post-secondary education institutions add to retail sales totals by bringing students into the area. Although students do not generally have a high income, they do spend a comparatively large portion of their income on taxable items such as food, entertainment and clothing.