Would you walk around the block to get to your next-door neighbor’s house? Of course not. Yet America’s system for taxing the ultra-rich, especially billionaires, works that same exact roundabout way.

For most of us, different taxes function in different manners. Sales taxes, for example, impact our spending decisions. Income taxes affect everything from how much we save and how many hours we work to when we retire. Property taxes influence the choices we make for where we live.

But these taxes don’t work that way for the ultra-rich. These deepest of pockets can essentially make decisions on spending, work, and retirement without regard to taxes. Taxes impact the ultra-rich in only one way: as the primary constraint on how much wealth they can eventually accumulate.

The ultra-rich, our politicians routinely declare, must pay their full “fair share” at tax time. What constitutes a “fair share”? Our pols would typically rather not get into that. We should.

The ultra-rich would be paying their fair share of taxes, one logical yardstick would suggest, if our taxes left their share of the nation’s wealth at a reasonable level.

The most direct way to achieve that reasonable result would be to tax either the wealth of the ultra-rich or the growth of that wealth. In the United States, unfortunately, we don’t go about taxing the enormously wealthy in that fashion. We rely exclusively instead on a mix of indirect measures — from taxes on personal and corporate income to levies on consumption and property — to hold in check the wealthy’s share of our nation’s wealth.

Before 1980, this indirect approach to taxing our richest worked reasonably well. Since 1980, our indirect approach has failed miserably. Between 1980 and 2018, the share of the nation’s wealth held by the top .01 percent has more than quadrupled, from 2.3 to 9.6 percent. The average household wealth of this ultra-rich group, some 13,000 households, now sits close to $1 billion.

Our continuing reluctance to tax wealth directly, our reliance on mostly only income and property taxes, has failed to keep the ultra-rich share of America’s wealth in check. Between 1980 and 2018, an Institute for Policy Studies briefing paper noted last year, our richest .01 percent would have had to pay at least 4 percentage points more of their total wealth in taxes each year to keep their wealth share from concentrating beyond its 1980 level.

Income, property, and consumption taxes could, of course, generate a “fair share taxation” of our ultra-rich. Indeed, we achieved that result before 1980, but only by taking the long way, by walking around the block to get to our next-door neighbor’s house. Yes, the long way can get us where we want to go. But taking this long route opens us up to infinitely more chances for things to go wrong.

Could we transition to taxes that take a more direct approach to constraining the wealth share of our ultra-rich? We certainly could. We have at least three choices.

The most direct would be a place a tax on the wealth of ultra-rich Americans, as Senator Warren and Representatives Jayapal and Boyle have proposed in their Ultra-Millionaire Tax Act. Under that proposal, ultra-rich households would pay an annual tax equal to 2 percent of their wealth between $50 million and $1 billion and 3 percent on their wealth in excess of $1 billion.

Some friends of grand fortune contend that this approach would be “too direct” and violate clauses of the U.S. Constitution that require “direct taxes” to be apportioned by state population. But many legal scholars challenge this analysis and vigorously defend the constitutionality of a wealth tax.

Other tax reformers suggest an option less vulnerable to constitutional attack: an income tax that redefines the “income” of the ultra-rich to include annual increases in wealth. Under this approach, the ultra-rich would be taxed directly on the growth of their wealth. Senator Wyden’s Billionaires Income Tax takes this route to “fair share taxation” of the ultra-rich. A tax along this line could hold the wealth share of the super-rich in check by limiting their after-tax wealth growth to no more than the growth rate of the nation’s total wealth.

A third option would build upon America’s existing estate tax, the direct tax we’ve had in place for over a century. Together with our existing gift and generation-skipping taxes, the estate tax imposes a levy on the transfer of wealth by the ultra-rich from one generation to the next. Working as originally intended, this once-per-generation trimming of wealth held by ultra-rich families could provide a direct approach to achieving fair-share taxation.

But sadly, as explained in the recent Americans for Tax Fairness Dynasty Trust Report, how we tax grand fortunes at death has broken down, to the point where even billion-dollar estates can escape taxation entirely. Still, appropriately strengthened, a revitalized estate tax could play a major role in achieving fair share taxation of the ultra-rich.

The bottom line: America’s indirect system of taxing the ultra-rich has been failing miserably for over four decades, producing a concentration of wealth at the top that threatens our democracy. We need a more direct approach to taxing the ultra-rich. That approach could be a direct tax on either the wealth of the super wealthy, the growth of their wealth, or the intergenerational transmission of their wealth — or some combination of all three. Let’s move in that direction.