There is no single structure for taxation rates worldwide; rather, it varies by country. For citizens residing in the United States, a progressive tax rate structure is applicable presently. In addition, there are many adjustments in the form of deductions and exemptions that affect an individual's income tax owed for a given period. Further, there are a number of sales and property taxes applied to certain purchased goods and real estate in the United States; primarily, these are levied by states. However, periodically the case for instituting a flat-rate tax is argued in Congress.

Expound on this topic comparing 3-5 advantages and 3-5 disadvantages of both the present progressive tax structure in the United States and the potential adoption of a flat-rate tax structure. Under which structure would more constituents be likely to evade taxes? Support your assertions with three reputable academic resources.