Writing a simpler, fairer tax code just sounds good. Who can argue with simpler and fairer? In Washington, that depends on who you ask.

The presidential campaign season is going to shift into high gear later this year, so lawmakers have only a few months left before all of the oxygen is sucked out of Washington. That diminishes any prospects of comprehensive tax reform becoming law during this Congress. Senate Majority Leader Mitch McConnell (R-KY) pretty much closed the door on that last week, saying: “we’re certainly not going to be able to be doing big, comprehensive tax reform with this president.” Policymakers are still talking about corporate tax reform, but it increasingly seems that the only piece of tax reform that still has a chance for this Congress are changes to our system of international taxation.

This is partly because the problems with our current international tax regime, like corporate inversions and the disincentive to repatriate foreign earnings, have gotten a lot of attention. It’s also because lawmakers continue to hold out hope that international tax reform is a way to pay for the perennial shortfalls of the Highway Trust Fund (HTF). While the problems with our global tax system are legitimate, earmarking any newly repatriated revenue for the HTF is a particularly bad idea that just kicks the trust funds problems down the road (but you already knew that from a Wastebasket last month).

One proposal for international tax reform some lawmakers are now floating is called a “patent box,” or as its advocates like to call it, an “innovation box.” This would involve creating an extra-low tax rate, like 10 percent as in the U.K., for businesses just on the income they derive from intellectual property, like a patent. In the U.S., companies can claim a tax credit for research-related expenses; a patent box would add a tax break on income from the result of that research. Some big U.S. businesses, like multinational high-tech and pharmaceutical firms, are pushing hard for the break.

Unfortunately, creating a patent box is neither simpler nor fairer. A patent box would require the IRS to identify which income a company is receiving that can be directly attributable to a piece of intellectual property, like a patent, and separate it out from other income the company reports. Even the existing research tax credit can be complicated by the subjective nature of what is and is not “research.” Adding another level of subjective analysis – which income is or is not attributable to a patent – would make the tax code more complicated, not less. When a patent expires for a pharmaceutical drug, for example, would the brand name company’s tax rate increase at the same time as generic competition enters the market?

It is not fairer because it obviously sets up a special tax treatment for only those companies that focus on intellectual property – there are plenty of corporate sectors with multinational companies that would not benefit from a patent box. In fact, this kind of special tax treatment for specific taxpayers is the problem of our existing tax code. The idea is to undo these special provisions, in order to make it simpler and fairer.

Even if international tax reform doesn’t happen during this Congress, decisions about the shape of a comprehensive deal are still being made now that will be difficult to reverse later, when comprehensive reform does happen. And Congress is spending a lot of time working on the issue of tax reform, even if it doesn’t have a lot to show for it.  Senate Finance Committee Chairman Orrin Hatch (R-UT) and Ranking Member Ron Wyden (D-OR) created tax reform working groups scheduled to report their recommendations in the next two weeks. House Ways and Means Committee Chairman Paul Ryan (R-WI) said this week that he wants to release a tax reform plan before the elections to show how Republicans can actually get things done.

Congress should strive to indeed make the tax code simpler and fairer. The challenge is going to be resisting the temptation to adopt policies that make for easy talking points, but that actually make the problem worse.