The 2020 Democratic field now teems with proposals to mitigate rampaging wealth and income inequality, from Kamala Harris’s plan to increase tax credits for low- and moderate-income families to Elizabeth Warren’s wealth tax. Such plans overlook, however, the principal set of relations that skew American capitalism upward: the ownership and operational control of business enterprises.

This failing is puzzling, because ownership and control so obviously matter. People who own companies, or who run them on the owners’ behalf, decide where and how much to invest. They decide how many people to hire, what sort of working conditions to provide, and—within broad limits—how much to pay those employees. All such decisions go a long way toward determining how well an economy serves its participants.

And decisions aside, ownership mightily affects the distribution of wealth and income all by itself. To take just one example, consider a successful midsize company—a regional restaurant chain, say, or a construction firm with $200 million in annual revenue and $10 million to $20 million in net profit. If it’s owned by one person or a small group, as is often the case, these owners may receive a million or more in income every year, and they have an asset likely worth tens of millions. Most of their employees will be lucky to earn $50,000 a year and save up a few thousand in a 401(k) plan. Surely broadening the ownership of business is a good idea.

The failing is doubly puzzling because we Americans have a better system of ownership staring us in the face—an economy in waiting, so to speak.

Close to 7,000 U.S. businesses are partly or wholly owned by a trust known as an employee stock ownership plan, or ESOP. The list of companies with full or majority employee ownership includes giant firms such as the Publix supermarket chain in the Southeast, with more than 200,000 employees; large and middle-market enterprises such as W.L. Gore & Associates, maker of Gore-Tex fabric, with nearly 10,000; and smaller companies such as King Arthur Flour (300) and New Belgium Brewing (800). These companies are typically more productive than their conventionally owned peers. They grow faster, pay higher wages, and are less apt to lay people off in a downturn. Successful ones—as most are—enable employees to build up serious wealth over time. A recent Rutgers study found that the average worker in a company with an employee stock ownership plan has already accumulated $134,000 in wealth just from his or her stake in the business. Some have a million or more.