Between the approaching federal income tax deadline and the recent release of documents dubbed the Panama Papers revealing secret offshore accounts used to hide fortunes by several world leaders and wealthy individuals, the issues of taxes and tax fairness are on the minds of many Americans.

Recent news reports also described action by the U.S. Treasury to stop or slow corporate tax avoidance schemes known as tax inversions, which involve a U.S. company merging with an often smaller foreign company based in a low-tax country such as Ireland. Tax inversions have accelerated in recent years, costing the U.S. Treasury hundreds of millions of dollars in lost corporate income taxes.

The Treasury action to block or slow tax inversions had the immediate effect of causing drug-maker Pfizer to issue a statement saying it will reconsider its proposed $160 billion merger with Allergen, which would have allowed Pfizer to shift its headquarters to Allergen’s base in low-tax Ireland.

Members of Congress, President Obama and most of the 2016 presidential candidates have talked about the need to stop tax inversions. The Treasury Department action should be followed up with legislation in Congress.

Tax inversions and other legal tax avoidance schemes are behind a decades-long decline in corporate income taxes. Over the past five decades or more, the percentage of federal tax revenues coming from corporate income taxes has fallen by about 50 percent.

Other recent tax-related news has focused on the Panama Papers, an anonymous release of millions of files containing evidence of current or former world leaders and other wealthy elites using secret offshore accounts to hide billions of dollars, robbing their home countries of tax revenue.

While the names revealed in the Panama Papers so far are mostly foreign, it’s been estimated that off-shore tax havens cost the U.S. Treasury $150 billion in lost revenue each year.

Beyond the exotic-sounding schemes of corporate tax inversions and off-shore tax havens, it’s important to not overlook the annual “tax gap.”

The tax gap is the difference between the IRS estimate for taxes owed and the actual amount collected. The latest estimate for the annual tax gap is $480 billion and is mostly due to underreporting of income, although some of the tax gap is also caused by nonfiling of taxes and underpayment of taxes.

The common thread in each of these issues is that there are costs associated with tax evasion and tax avoidance. The range of actions from illegal tax evasion to legal tax avoidance — including corporations with teams of accountants and lawyers exploiting the many loopholes in the federal tax code — all impose a cost on individual taxpayers. For every dollar of corporate taxes saved by a tax inversion or exploitation of tax loopholes, another dollar will be paid by honest individual taxpayers — or the national debt will increase.

The subject of taxes, the loophole-ridden tax code and finding a fair balance between corporate and individual tax contributions should be part of the debate in the 2016 presidential campaign. Voters should press for solutions to close the tax gap, to give the IRS more tools to increase compliance and collections, while making it harder for tax cheats to get away with not paying their fair share.

Tax evasion and tax avoidance is not just an economic issue, it’s about fairness.