New federal tobacco regulations contain a cost-benefit calculation known as the “happiness quotient,” which weighs the health benefits of reduced smoking against the loss in pleasure that smokers suffer when they quit. This calculation could make it harder for the Food and Drug Administration (FDA) to take strong action against tobacco companies, critics say.

The calculation assumes the benefits from reducing smoking must be discounted by 70 percent to offset the loss of happiness smokers experience when they quit, according to The New York Times.

The risk-benefit calculation could make the new regulations much more susceptible to legal challenges, experts told the newspaper. A group of economists submitted a paper to the FDA this week saying the happiness quotient was much too high. They called on the agency to change the quotient before the regulations take effect. The public comment period for the regulations closes on Friday.

Every set of federal regulations with more than a $100 million effect on the economy requires an analysis, in order to prevent regulations that have high costs and low benefits, the article notes.

The cost-benefit analysis is part of a proposal announced by the FDA in April that would allow the agency to regulate e-cigarettes. The proposed rules would ban the sale of e-cigarettes, cigars and pipe tobacco to anyone under age 18.

FDA spokeswoman Jennifer Haliski told the newspaper there is “still a great deal of uncertainty” surrounding the calculation, and that the agency was helping fund research to explore the issue.

So far, more than 69,000 public comments on the proposed tobacco regulations have been received. The rules are scheduled to become final by the summer of 2015. Experts said legal challenges are expected soon after.

Economists who opposed the happiness quotient for smoking said it incorrectly assumes people make rational, well-informed choices they will not later regret. They point out most people who smoke start before they are 18, when their judgment is impaired. Once they decide to quit, they are already addicted.