Last week, we launched the U.S. Tax & Spending Explorer on the EPI website. It’s an interactive web feature designed to shed light on how the government (mostly the federal government) raises and spends money and how changes in taxes and spending over time either increase or decrease income inequality.

There’s enough granular detail in the feature that everybody might have different takeaways from visiting it. But here’s what strikes me looking at this data:

Together, taxes and spending significantly reduce inequality at any given point in time relative to a world with a much smaller federal footprint. That’s the good news. The bad news is that since 1979 the inequality-reducing effect of taxes and spending hasn’t grown that much—but inequality has grown, a lot. We should use the proven inequality-fighting lever of a larger tax and spending system to combat the inequality that has risen so fast in recent decades.

Most of the inequality-reducing benefit of the taxing and spending done by the federal government happens on the spending side. People often have wildly incorrect ideas about what the federal government spends the most money on, but the large majority of this spending is accounted for by well-known and broadly-popular programs like Social Security, Medicare, Medicaid, and the Affordable Care Act. Together, just these programs alone constitute almost 67% of federal spending. These programs, along with other safety net programs and social insurance programs, constitute “transfer” payments that directly support households’ incomes and living standards. These transfers are very effective in reducing inequality, with the large majority going to households in the bottom two-fifths of the income distribution.

The federal tax system overall is progressive, with higher-income households paying more than low- or moderate-income households. Yet the tax rate faced by the richest households, instead of rising steadily to combat the rise in inequality since 1979, has just fluctuated (sometimes a little up and sometimes a little down) in a narrow band over that time. By 2015, for example, the overall federal tax rate faced by the top 1% was actually a bit lower than the rate in 1979. In short, taxes on the richest households have been a radically underutilized tool in the effort to push back against the rising inequality of recent decades.

Within the federal tax system, some of the most progressive elements—like the corporate income tax and the estate tax—have been slowly (and sometimes not so slowly) throttled over time, accounting for a smaller and smaller share of federal revenue. A less progressive feature of the federal tax code—payroll taxes that fund Social Security and Medicare—has risen in importance.

The still-progressive federal tax system is perhaps underappreciated by many households who face a regressive tax burden overall due to state and local systems that rely on sales and property taxes. The overall burden of taxes at the local, state, and federal level is quite flat and does much less to fight inequality than the federal system alone.

Finally, a surprising feature of the U.S. data is how stable taxes and spending have been as a share of the overall economy for decades. The experience of other rich countries highlights that taxes and spending could be substantially higher than what prevails in the U.S. today. One potential benefit of a larger fiscal footprint could be a substantially improved effort in fighting poverty. Compared to our international peers, our fiscal system wages only the weakest of fights against poverty.

All in all, our U.S. Tax & Spending Explorer shows that the federal tax and spending system is the biggest tool we use to combat inequality—but it could and should be quite a bit bigger. Identifying which parts of our system should be changed to get the most bang for your buck in reducing inequality requires some real granular study, so, check it out!