Amazon’s taxes have become a campaign issue. In last week’s Democratic debates, two different candidates (Cory Booker and Andrew Yang) called out Amazon for paying $0 in federal income taxes last year, even after listing $4 billion in profits. Joe Biden, Elizabeth Warren, and President Trump himself have brought up the same point at various points on the campaign trail, always directed at Amazon. In a CNN interview after the second debate, Bernie Sanders singled the company out as an example of a broken tax code, saying simply, “I’m going to tax them.”

“We pay every penny we owe in corporate taxes including $2.6 billion over the past three years,” Amazon said when reached for comment. “We’ve invested $270 billion in the US since 2010 and created more than 275,000 jobs.”

But there’s an awkward truth behind the political back-and-forth: we don’t know what Amazon’s tax bill really is. Like every other company in America, Amazon’s tax returns are private, legally considered to be a trade secret. We don’t know which tax breaks they’re taking, or how they’ve structured their finances to avoid various taxes in favor of others. If Amazon says its tax bill was lower because of investments, we simply have to take the company at its word.

We can only make rational policy decisions if the public knows what companies are actually paying

Most of what we know about Amazon’s taxes comes from the company’s SEC filings, helpfully explained in this Wall Street Journal piece. Those filings list the company’s “current provision” for taxes — basically the money it expects to send to the US government this year. In the filing covering 2018, that number was negative $129 million, a net tax benefit for the company, levied against $11 billion in profits. That’s where candidates are getting the idea that Amazon is skimping on its taxes — but that number doesn’t tell you Amazon’s actual tax burden any more than your Apple receipt tells you the actual cost of your phone. The current provision could include newly settled tax disputes from previous years, or be lowered by deferments into the future. There are also a mess of thinly disclosed local and foreign tax payments, which are where Amazon gets the higher $2.6 billion number. But if you’re looking through that data for a sense of whether Amazon is paying its fair share, you’re in for a hard time.

That’s a bizarre state of affairs, and it shouldn’t continue. Amazon’s tax filings are a matter of legitimate public interest, and major politicians are forced to guess about them. Amazon is a massive, world-shaping company, and it’s entirely fair to ask whether they’re paying their fair share. But whichever side of the tax debate you’re on, we can only make rational policy decisions if the public knows what companies are actually paying and why. The best way to do that is to get the information straight from the source.

It’s time for America to see Amazon’s tax returns.

Of course, this isn’t just about Amazon. The company has sparked a broader conversation about corporate tax fairness, and that conversation should be grounded in hard data about what companies are paying. At least 60 companies zeroed out their federal income taxes in 2018 — including Netflix, Chevron, and Halliburton — for a total of more than $20 billion in collective deductions. Disclosing all or most of the information on corporate tax returns could uncover a shocking number of loopholes, even if the requirement were limited to only the largest corporations or those taking the largest deductions.

This kind of measure has been proposed before

That might sound strange, but this kind of measure has been proposed before — and not just by Democrats. Before 1976, corporate tax returns were broadly considered part of the public record (albeit with heavy exceptions), and disclosure provisions have been floated a number of times in the years since. In the wake of the Enron and WorldCom accounting frauds in 2002, Sen. Chuck Grassley (R-IA) wrote to the US Treasury to suggest that publishing summary versions of large companies’ tax returns might prevent future scandals. Just last year, the Congressional Research Service wrote a report assessing the idea, concluding that mandatory disclosure of more tax information could show how companies were benefiting from specific tax provisions, and generally demystify the tax code. “Increased disclosure could assist policymakers when drafting legislation,” the report found, “and also help shed light on corporate tax planning, which may be useful to the general public.”

Deductions are particularly important, according to Matthew Gardner of the Institute on Taxation and Economic Policy. In theory, the tax rate on corporate income is 21 percent (down from 35 percent after the 2018 tax cuts), but almost no corporations actually pay that rate, ending up with much lower direct payments of the kind disclosed by Amazon. In between, there are lots of tax deductions, ranging from legitimate capital investments to more arbitrary deductions like the accelerated depreciation of assets. But we simply have no clear picture of which deductions Amazon is taking.

For the most part, policymakers are in the same boat. As a legal matter, Treasury officials and members of the tax committee have access to all filed tax returns, but they’re considered so sensitive that the information usually doesn’t circulate. As a result, most of the staffers and think tanks that shape policy are working in the dark.

“If you’re a policymaker right now in 2019 and you want to know which tax breaks that we enacted are reducing Amazon’s effective tax rate, you cannot find out with this information,” says Gardner. “There are disclosures in the annual report that give you a rough indicator of the scale of tax avoidance, but you can’t use it to figure out what we could fix.”

We need to know which deductions Amazon is taking and why

When politicians like Warren complain about Amazon not paying taxes, the real argument is that the company is abusing the tax deduction system, exploiting poorly designed deductions and using political influence to keep those loopholes open. But if you’re making that case, it’s not enough to simply say Amazon took a lot of deductions. We need to know which deductions Amazon took and why. The only way to know that is to see the filing itself. (It should go without saying that all these arguments apply equally well to a president’s tax returns.)

More transparency could also shed light on the thornier topic of foreign tax shelters, which most companies currently report to the SEC as a single number for all non-US income. “The number one ask is, you want to break down this bucket of foreign income into something other than just ‘the rest of the world,’” says Gardner. “You’d want to know, at least for a specific known tax haven, what fraction a company’s employees, pre-tax income, and tax is attributable to, say, Bermuda or the Cayman Islands.” When that information has been made public — most notably under the OECD’s recent anti-tax-shelter framework — the results have been promising, with billions flowing back into national treasuries.

The main reason we don’t publish tax returns already is that it would turn up some embarrassing secrets. Corporations typically treat taxes as an expense to be minimized, setting loose armies of lawyers and accountants to ensure they pay the minimum required by law. While legal teams exploit loopholes, political teams lobby to keep them open. None of this is new or unique to Amazon, but pulling back the curtain on it all would be embarrassing across the board. It also might reveal corporate secrets beyond just tax tricks, including investments and projects that companies would prefer to keep to themselves. But what’s bad for companies like Amazon could be good for the public at large. Tax secrets aren’t just shameful; they’re harmful.

In some ways, Amazon makes an easy villain. The political mood is turning against tech companies, and Amazon’s low tax bill seems like an obvious sign of a rigged system, just like Facebook’s quietly targeted ads or YouTube’s impenetrable algorithm. But the measures to address platform problems are usually ambitious to the point of implausibility, requiring a revolution in antitrust law or a modern-day telecom act. In comparison, making tax returns public is a relatively easy lift. The Treasury already has this information. We’re already looking for it, even talking as if we have it. Releasing it will mean standing up to a lot of corporate blowback, but so will any meaningful reform. All this particular reform needs is passing a law and publishing a file. If we want to make sure Amazon’s paying its fair share, that’s where we should start.