Question: What is worse than an election promise of bad tax policy?

Answer: A campaign promise by both major presidential candidates to pursue the same bad tax policies.

Vice President Kamala Harris could have made so many promises to win votes during her recent campaign trip to Las Vegas, but unfortunately she chose to promise to exempt tips from federal taxes.

That’s exactly what former President Donald Trump promised during a similar trip to Las Vegas earlier this year. As a campaign strategy, it was clever: neutralize your opponent by promising what he promised.

But as public policy, it’s a bad idea. It was a bad idea when Trump said it, and it’s a bad idea when Harris says it.

It is, however, good policy. There are far more service and hospitality workers in Las Vegas than economists, so the “don’t tax tips” proposal is met with thunderous applause every time.

However, the economists will have the final say.

As news reports have made clear, both liberal and conservative economists agree on this point. A tax exemption on tips would increase the national debt at a time when it is already a problem. This, in turn, could hurt Social Security and Medicare (depending on how the exemption is designed) at a time when both programs are facing looming cash shortages.

According to Politico, experts are trying to calculate the total cost to the treasury. The Committee for a Responsible Federal Budget estimates it could be between $100 billion and $250 billion over a 10-year period. But that depends on the details, which are scant so far from both campaigns. Moreover, it’s easy to underestimate the impact, since such a policy change would likely affect citizens’ behavior over time and make the economy more based on tips.

“It’s one bad idea piled on top of another,” Howard Gleckman, senior fellow at the Tax Policy Center, told Politico. “There aren’t many tax benefits.”

Experts say many tips are already unreported. Exempting them from tax would be a big incentive for employers and employees to make even more tip-based jobs. Some workers who currently don’t receive tips, such as auto mechanics, could resort to this model to avoid taxes.

If you don’t like the way waiters – from hairdressers to fast-food workers – ask for tips these days using electronic devices, this idea would probably become a widespread practice.

NPR quoted Steve Rosenthal, senior fellow at the Urban-Brookings Tax Policy Center, as saying the rule would create problems of inequity. A waiter in South Carolina, whose salary is structured so that tips make up a large part of his pay, would benefit more than one in California, where tips make up a smaller part of pay.

“Why are employees who provide similar services treated so differently from a tax perspective just because some get tips and others don’t?” he asked.

The biggest challenge with such a rule may be that it makes government oversight and regulation more difficult. Many tips are paid in cash. Reporting is unreliable and inconsistent from business to business. Some businesses collect all tips and distribute them equally to employees. Others let employees keep what they receive.

“How can we determine who is receiving a tip and when that tip exceeds the wage threshold?” Rosenthal told NPR. “For example, how can we prevent investment bankers from receiving tips? And if we set income thresholds, wouldn’t we expect low-income workers to simply demand a tip instead of compensation?”

We’d like to say this is little more than a passing campaign fad, but Republican Senator Ted Cruz of Texas has already introduced a bill that would exempt tips from income taxes, but would still subject them to payroll taxes for Social Security and Medicare.

Plus, the idea is generally popular with the public. Newsweek just published a poll by Redfield & Wilton Strategies showing that 67% of Americans are in favor of making tips tax-free.

But tax policy should be based on principles, justice and fairness, not just popularity, and should cause as little damage to the economy as possible.

A general income tax cut could stimulate the economy by creating incentives for production. Exempting tips would only distort the economy and create inequities.

“We’re in an election season – a fool’s season,” Rosenthal told NPR. “A race to the bottom would be a better description of tax policy here.”

A much better campaign tactic would be for each candidate to outdo the other on how to reduce the annual budget deficit and reduce the debt. That probably wouldn’t get much applause, but it would ensure that everyone wins when the economists have the final say.