In the period before the FairTax is implemented, there could be a strong incentive for individuals to buy goods without the sales tax using credit. After the FairTax is in effect, the credit could be paid off using untaxed payroll. If credit incentives do not change, opponents of the FairTax worry it could exacerbate an existing consumer debt problem. Proponents of the FairTax state that this effect could also allow individuals to pay off their existing (pre-FairTax) debt more quickly, and studies suggest lower interest rates after FairTax passage.