The good news is that we can fix tax injustice, right now. There is nothing inherent in modern technology or globalization that destroys our ability to institute a highly progressive tax system. The choice is ours. We can countenance a sprawling industry that helps the affluent dodge taxation, or we can choose to regulate it. We can let multinationals pick the country where they declare their profits, or we can pick for them. We can tolerate financial opacity and the countless possibilities for tax evasion that come with it, or we can choose to measure, record and tax wealth.

If we believe most commentators, tax avoidance is a law of nature. Because politics is messy and democracy imperfect, this argument goes, the tax code is always full of “loopholes” that the rich will exploit. Tax justice has never prevailed, and it will never prevail.

For example, in response to Elizabeth Warren’s wealth tax proposal — which we helped develop — pundits have argued that the tax would raise much less revenue than expected. In a similar vein, world leaders have become convinced that taxing multinational companies is now close to impossible, because of international tax competition. During his presidency, Barack Obama argued in favor of reducing the federal corporate tax rate from 35 percent to 28 percent, with a lower rate of 25 percent for manufacturers. In 2017, under President Trump, the United States cut its corporate tax rate to 21 percent. In France, President Emmanuel Macron is in motion to reduce the corporate tax in 2022 to 25 percent from 33 percent. Britain is ahead of the curve: It started slashing its rate under Prime Minister Gordon Brown in 2008 and is aiming for 17 percent by 2020. On that issue, the Browns, Macrons and Trumps of the world agree: The winners of global markets are mobile; we can’t tax them too much.

But they are mistaken. Tax avoidance, international tax competition and the race to the bottom that rage today are not laws of nature. They are policy choices, decisions we’ve collectively made — perhaps not consciously or explicitly, certainly not choices that were debated transparently and democratically — but choices nonetheless. And other, better choices are possible.

Take big corporations. Some countries may have an interest in applying low tax rates, but that’s not an obstacle to making multinationals (and their shareholders) pay a lot. How? By collecting the taxes that tax havens choose not to levy. For example, imagine that the corporate tax rate in the United States was increased to 35 percent and that Apple found a way to book billions in profits in Ireland, taxed at 1 percent. The United States could simply decide to collect the missing 34 percent. Apple, like most Fortune 500 companies, does in fact have a big tax deficit: It pays much less in taxes globally than what it would pay if its profits were taxed at 35 percent in each country where it operates. For companies headquartered in the United States, the Internal Revenue Service should collect 100 percent of this tax deficit immediately, taking up the role of tax collector of last resort. The permission of tax havens is not required. All it would take is adding a paragraph in the United States tax code.

The same logic can be applied to companies headquartered abroad that sell products in America. The only difference is that the United States would collect not all but only a fraction of their tax deficit. For example, if the Swiss food giant Nestlé has a tax deficit of $1 billion and makes 20 percent of its global sales in the United States, the I.R.S. could collect 20 percent of its tax deficit, in addition to any tax owed in the United States. The information necessary to collect this remedial tax already exists: Thanks to recent advances in international cooperation, the I.R.S. knows where Nestlé books its profits, how much tax it pays in each country and where it makes its sales.