A Loophole for Poor Mr. Paulson

Generally, the US government pays far less for high-level employees than you can earn in the private sector. But if you're extremely rich, there is a little-known benefit. Conflict-of-interest rules for government positions allow government employees subject to them to sell assets and reinvest them in cash/Treasuries/mutual funds/ETFs without paying capital gains taxes upon selling those assets. The tax is just deferred - you'd still have to pay capital gains taxes when selling the new assets, with the basis being the original purchase price of the assets you were forced to sell.

So the upshot is that it makes sense for extremely rich people in private industry to take government positions where there would be a conflict of interest with their previous company. This allows them to diversify their assets in a tax-efficient manner.

When you die, the basis for capital gains is reset or "stepped up" to the current price of the assets upon death, which means your heirs or estate can immediately sell the assets completely tax-free. This doesn't differ between diversified and non-diversified assets. But taking a government job allows extremely rich people to get out of a concentrated asset position, with the risk inherent to a single stock's performance over decades, and into the much more predictable world of diversified Treasuries or stock index ETFs.