American wealth dynasties are on the rise as the heirs and heiresses of family fortunes watch their wealth skyrocket. Meanwhile, most families struggle to make ends meet.

What, besides simply hiking income taxes, might be done?

A new report I co-authored, Billionaire Bonanza 2018, looks at rising wealth inequality with an eye toward solutions. Included in our key findings is the fact that the three wealthiest families in the U.S.—the Waltons (Walmart), the Kochs, and the Mars—have seen their wealth increase nearly 6,000% just in the past generation.

Median household wealth over the same period went down by 3%.

In the wake of the last Gilded Age—the period from the 1890s to the late 1920s when inequality rivaled periods we see today—reformers used the tax code to break up the immense wealth dynasties of that era. They passed the federal estate tax, a levy on the intergenerational transfer of wealth, in 1916, and instituted high marginal income tax rates on the wealthy, spiking from 25% in 1931 to 63% the next year, and rising as high as 94% on the richest households in 1944 and 1945.

Read the full article at Fortune.

Josh Hoxie directs the Project on Opportunity and Taxation at the Institute for Policy Studies.