The city of Carina is considering implementing an Alternative Minimum Tax (AMT) for taxpayers earning more than 90% of the population, those individuals who earn more than $350,000 annually. Under this tax plan, Carina citizens in the AMT bracket would be exempt from paying taxes on the first $80,000 of their income and be taxed at a flat rate on the income thereafter. People paying the AMT would not be given allowances regular taxpayers are, such as deductions for children, healthcare expenses, or college tuition.
Which of the following would be most important to determine in order to evaluate whether implementing the AMT plan would be profitable for the city of Carina?