Presidents Ranked By Level Of Income Inequality: Gini Ratio Of Families, End Of Term

1. .349 JFK/LBJ (least income inequality)

2. .359 Truman

3. .363 Nixon/Ford

4. .369 Carter

5. .374 IKE

6. .401 Reagan

7. .429 Bush 1

8. .435 Clinton

9. .443 Bush 2

10. .450 Obama, to date (most income inequality) 

Presidents Ranked By Change Of Income Gini Ratio Of Families In Post-War

1. JFK/LBJ       -6.6%

2. Truman       -5.0%

3. Clinton       +1.3%

4. Obama        +1.5% (to date)

5. Carter         +1.6%

6. Bush2          +1.8%

7. Nixon/Ford +4.0%

8. IKE              +4.1%

9. Bush1          +6.9%

10. Reagan      +8.6%

Inequality of market income decreased most under Kennedy/Johnson and increased most under Reagan. The measure is before taxes and transfers, however. The Organization for Economic Cooperation and Development figures after taxes and transfers for certain periods may be observed here. See the helpful discussion by Tim Worstall, here, including this:

"[E]ven in the post-tax and post-benefit numbers the US is still an outlier in the statistical methods used. In looking at inequality, poverty, in the US we include the cash that poor people are given to alleviate their poverty. But we do not include the things that people are given in kind: the Medicaid, SNAP, Section 8 and so on. It’s possible (I’m not sure I’m afraid) that we don’t include the EITC either. We certainly don’t in the poverty statistics but might in the inequality. All of the other countries do include the effects of such policies. Largely because they don’t offer benefits in kind they just give the poor more money and tell them to buy it themselves. This obviously turns up in figures of how much money the poor have."

That said, inequality of market income hasn't gone up very much in the twenty years since 1993, contrary to President Obama's recent comments here. 

The president might want to consider that Bill Clinton did a better job of reducing income inequality than he has. But, then again, Bill Clinton did a better job than Obama in most everything, and ranks number two behind Truman overall for the best economy in the post-war.