The median respondent in a Washington State University-led survey would pay a 10 percent premium for tires labeled "salmon safe," about $76 more for a set of four, according to a study published in the journal Marine Resource Economics.

Joe Cook, a professor in WSU's School of Economic Sciences and lead author of the study, and co-author Wisnu Sugiarto, a professor at Whitman College and a former WSU graduate student, surveyed nearly 700 people in California, Oregon and Washington. The premium was measured against the price respondents most recently reported paying for tires. About 25 percent said they would pay a $225 premium for a set of four.

"The tire doesn't exist yet, but we wanted to know how the general population might value the tire after it's been developed. As the tire industry explores reformulation, we hope this demonstrates there is a potential market for 'eco-labeled' tires," Cook said.

The work was funded by the nonprofit Salmon Safe. It follows earlier research, co-led by WSU scientists, that found 6PPD, a compound used to keep tires from breaking down too quickly, is toxic to coho salmon when tire debris reaches freshwater streams. Tire manufacturers are working on formulations that would eliminate the compound.

Cook, who is based at WSU's Puyallup Research and Extension Center, stressed that the findings describe a hypothetical, eco-labeled product, not the price effects of regulation.

"This study is about voluntary eco-labeling for a hypothetical product," Cook said. "We aren't saying that prices would go up this amount if 6PPD is regulated out of tires. That ultimately would depend on what it costs for tire manufacturers to reformulate and how competitive the tire industry is."

"Studies like this are important for groups who care about salmon and for members of the tire industry," said Raj Khosla, Cashup Davis Family Endowed Dean of WSU's College of Agricultural, Human, and Natural Resource Sciences.