The idea he and others have since developed in a long string of studies is that differences in wages show the value that workers place on avoiding the risk of death. Say that companies must pay lumberjacks an additional $1,000 a year to perform work that generally kills one in 1,000 workers. It follows that most Americans would forgo $1,000 a year to avoid that risk  and that 1,000 Americans will collectively forgo $1 million to avoid the same risk entirely. That number is said to be the “statistical value of life.”

Professor Viscusi’s work pegs it at around $8.7 million in current dollars.

Before the current administration, only the E.P.A. had fully embraced this methodology. Other agencies relied instead on the results of surveys asking Americans how much they would spend to avoid a given risk. This technique tends to produce significantly lower results. An even older technique, which yields even lower numbers, is to sum the wages lost when a worker dies. In 2000 the E.P.A set a baseline of $7.8 million, updated to current dollars. But in 2004, the office that issues clean air regulations reduced that baseline by $500,000 in an analysis of proposed limits on emissions from industrial boilers.

Last year, the E.P.A. directed its various offices to return to the 2000 baseline, adjusting that figure for inflation and wage growth. In some recent studies, the E.P.A. has used a figure of $9.1 million after making those adjustments.

The agency said at the same time that it was working to set a new standard. In a white paper issued in December, it raised the possibility that people might place a higher value on avoiding a slow death from cancer than a quick death in a car accident. It also broached a concept it described as “altruism,” the idea that people may place a higher value on the common good than on their own survival.

John D. Graham, who oversaw the use of cost-benefit analysis during the George W. Bush administration, said that the scientific justification was “quite strong” for raising the values used by the Transportation Department, but he cautioned that the E.P.A. was going too far.

“Why should the same clinical condition be valued differently at different federal agencies?” Mr. Graham, now dean of the School of Environmental and Public Affairs at Indiana University, asked in an e-mailed response to questions.

Many experts similarly ask why life itself should be valued differently. Agencies are allowed to set their own numbers. The E.P.A. and the Transportation Department use numbers that are $3 million apart. The process generally involves experts, but the decisions ultimately are made by political appointees.