Most of us may not have noticed, but the rising tide of income inequality is engulfing the super rich as well.

As The Times put it recently: “For decades, a rising tide lifted all yachts. Now, it is mainly lifting megayachts. Sales and orders of boats longer than 300 feet are at or near a record high, according to brokers and yacht builders.”

The same is happening to private planes: “Sales of the largest, most expensive private jets — including private jumbo jets — are soaring, with higher prices and long waiting lists. Smaller, cheaper jets, however, are piling up on the nation’s private-jet tarmacs with big discounts and few buyers.”

The underlying dynamic is the same, and it affects everyone, though obviously it affects us differently — depending where we are on the spectrum of wealth. The poor may have difficulty scraping together the money to buy a new car – or even repair the one they have — but the problems of the rich are different.

“The wealth of the top 1 percent grew an average of 3.9 percent a year from 1986 to 2012, though the top one-hundredth of that 1 percent saw its wealth grow about twice as fast. The 16,000 families in that tiptop category — those with fortunes of at least $111 million — have seen their share of national wealth nearly double since 2002, to 11.2 percent.”

Thomas Piketty, the French economist, recently clarified how existing capital grows faster than wages, countering some assumptions that had entered mainstream thinking. And he pointed out that the structure of taxes could have a major impact on the growth of wealth. But it is still striking how little we appear to want to do about that, how we are content to let the gap widen and widen.

Could it be that so much of that extra money ends up in the pockets of lawmakers in the form of campaign contributions? Perhaps, as a result, legislators have little interest in tax reform?

But another interesting question is why do people want so much more money than they could ever spend?

After a point where basic needs have been satisfied, money begins to have a purely symbolic meaning, and and shape the desire for more. There are billionaires who scrutinize the Forbes list of wealthiest Americans, just as sixth graders scrutinize test scores to see who came out on top. And there is no end to how much money is needed to triumph over others. Even if you have more money than anyone else right now, who can guarantee that someone else will not come along soon to trump your achievement?

But there is another factor. The growing wealth disparity means that we are in the process of creating a new class system. The money being made now, as a result, becomes the foundation of new dynasties, a way of ensuring that one’s descendants will continue to be secure and powerful for generations to come.

So this is a relatively rare moment in history in which a new social order is being created. That raises the stakes. A few billion dollars can give your descendants a permanent place in that order. On the other hand, failing to succeed on that level means that your children and their children will have to make it on their own.

For some, that’s a real incentive.