The tax gap is the gap between personal income and adjusted gross income (AGI), and it is currently the highest it has been in 46 years worth of data analyzed by the Bureau of Economic Analysis. AGI is the key before-tax definition of income, used by the IRS in the calculation of individual income tax liabilities, while personal income is often used in examining trends in national economic output, consumer spending, saving, and investment. In other words, the tax gap is the difference between the amount of money people actually have, and the amount of money they say they have in their tax returns. The gap is currently at 14.4%, and is up from 10.7% in 2000.