There are income restrictions when it comes to Roth IRA contributions. If you are single, you must have a modified adjusted gross income under $133,000 to contribute to a Roth IRA for the 2017 tax year, but contributions are reduced starting at $118,000. If you are married filing jointly, your MAGI must be less than $196,000, with reductions beginning at $186,000. What could be the rational for these restrictions?