Final answer:
Mandatory outlays are predicted to grow over the next decade due to the aging population, insufficient payroll taxes, and difficulty in enacting major reforms to entitlement formulas.
Step-by-step explanation:
Mandatory outlays are predicted to grow over the next decade due to a combination of factors. First, the aging population, particularly the baby boomer generation, will lead to increased demand for entitlement programs such as Social Security and Medicare. Second, the current level of payroll taxes that support these programs is not sufficient to cover the projected expenses, resulting in larger budget deficits. Lastly, major reforms to entitlement formulas are difficult to enact, allowing funding for mandatory spending to continue on autopilot.