Task:
Mona, a calendar-year taxpayer, uses the cash-basis method of accounting for her whole proprietorship. In late December she received a $20,000 bill from her accountant for consulting services related to her small business. Mona can pay the $20,000 bill any time before January 30 of next year without penalty. Assume her marginal tax rate is 40 percent this year and next year, and that she can earn an after-tax rate of return of 12 percent on her investments.
When should she pay the $20,000 bill - this year or next? Please explain.