Depending on where you are, talking about tips can be a very sensitive topic. Take for example a Hispanic working in a restaurant in the United States. Newcomers may find themselves in an uncomfortable position if they don’t know what the tradition in the country requires. This is because tipping is not standardized, but it is fundamental to the economy and culture in the US. Donald Trump and Kamala Harris know this all too well.

A common ground. It’s hard to explain how far apart the policies that both politicians are pursuing are (at least on paper). That’s why it’s strange that both campaigns come to the same conclusion: Workers’ tips shouldn’t be taxed. In other words, they both propose eliminating tip taxes.

While it seems obvious that this initiative is an effort to attract the attention of Americans who work in service industries—restaurant workers, waiters, hairdressers, manicurists, taxi drivers, and others who often receive a significant portion of their income in tips—there are many pitfalls to the idea for those who think that lower taxes mean more money in their pockets.

Go back to the past. That’s the basic idea. The national debate comes at a time when electronic payments are making it easier to track tips, increasing the risk of underreporting or underreporting. Tips, especially in cash, were often unreported payments to the IRS. So they were notorious for going unreported.

Under current law, employees must report all tips over $20 per month to their employers. The federal government then collects a portion through income and payroll taxes, which fund programs like Social Security (states also have their own income tax rules).

Financial impact. It’s not clear exactly what the initiative would mean if it were to go ahead. Some of the congressional proposals focus solely on income taxes, while others would exempt tips from the payroll tax. That’s one of the keys, because neither candidate has a clear idea.

However, the Tax Foundation estimates that any changes would cost the Treasury at least $107 billion over a decade; other estimates are higher.

While repealing tip taxes may seem politically straightforward, some analysts say it’s not good policy—quite the opposite. As Keith Hall, a labor economist at the Mercatus Center at George Mason University and former commissioner of the Bureau of Labor Statistics, put it, “Let them tell us how they’re going to pay for it.”

Same salaries, different levels. As Fortune tells us, even if we didn’t look at the cost to coffers over the next decade, the proposal would represent a radical change in how tipped workers are paid and how the U.S. tax system works, with workers earning the same amount of money paying taxes at different levels.

In other words. If the policy becomes law, millions of workers will be encouraged to give up wages or hourly rates to reduce their income taxes, and business owners will likely be happy to be forced to reduce their own payroll taxes.

An issue of equality. As Hall puts it, there are two principles that make the income tax system efficient and fair. First, people who make more money pay more in taxes; second, people who make the same amount of money pay the same amount in taxes. “This is not an economic issue; it’s an equity issue. It’s also a big part of people’s willingness to pay their taxes.”

The problem of manipulating clues. The problem that both candidates must solve has been compounded. The country’s tax system is rife with legal solutions for the wealthy, as is demonstrated by the fact that many of the wealthiest people in the United States pay very little federal income tax, and sometimes nothing at all. The tips are no less susceptible to manipulation, according to a report by the progressive think tank Center for American Progress.

In other words, the initiative could also be used to commit tax abuses by the wealthy. In this regard, both Trump and Kamala Harris’ teams have expressed concern that they would close any loopholes, but again in vague terms.

Less taxes overall. The last of the legs to clarify is perhaps the most important. Fortune spoke to several business owners whose employees make money from tips, and they all supported the policy proposal but were concerned that it could encourage some form of cheating in the system.

Like? Carl Sobocinski, owner of five restaurants in Greenville, South Carolina, explains: “Both owners and employees may be tempted to change their compensation structure to pay workers more in tips than in wages, which would still be taxable.” What the businessman meant was to be careful not to let people skirt the law to pay less in taxes. The background: an even bigger billion-dollar hole for the federal government, because it would lose both the income tax on employees and the payroll tax that the company would have to pay.

Domino effect. As an economist, Hall sees the ripple effects of such a big change affecting millions of workers throughout the economy. Real wages for tipped workers will increase, but likely without an increase in the cost of everyday goods, “which is what usually happens when wages go up,” he explains.

While this may seem like a good thing, in theory it doesn’t mean that no one is paying. “The government will foot most of the bill. “There may actually be less pressure on the price of things like food, but of course taxpayers are paying the price for that.”

Image | Tomwsulcer, alan.light

At Xataka | Tips are out of control in the United States: now even vending machines want them

On the Xataka | The world’s largest cruise ship also has the most expensive room: over €100,000 including tips