Retail gas prices in St. Joseph rose 15 cents in the past week, the biggest jump in more than a year, raising fears that consumers could curtail holiday spending just as the recession eases.

The average retail price for regular unleaded gasoline was $2.54 per gallon on Tuesday, passing the peak summertime level of $2.51 per gallon, according to AAA Missouri. The auto club bases its survey on credit card transactions at gas stations.

“This is an anomaly,” said Mike Right, a spokesman with AAA Missouri. “Going forward for the rest of this year, we’re likely to be paying higher prices for gasoline than what we paid last year.”

Economists cite several reasons for the current surge of gasoline prices.

Refiners across the nation have cut back on production. That has artificially increased the price of gasoline at a time when they say their profit margins are low.

Also, the dollar is weak. And since crude oil is bought and sold with the dollar, traders with other currencies can buy more with less.

“International speculation in the oil market continues,” said Juan Pablo Fuentes, an economist with Moody’s Economy.com who writes about energy issues.

“Most investors believe the recovery in the global economy is going to drive oil consumption in the next few years,” he said. “If the worst of the recession has passed, oil consumption is going to rebound, and that’s what’s happening.”

Though motorists are currently paying less than what they paid for gasoline at this time last year, a gradual increase could prompt consumers to cut back on holiday spending. This has already been a bad year for employment, home values and 401(k) accounts.

“If they’re spending more money at the pump, they’re going to be less willing to go out to the malls to spend frivolously,” Ryan Sweet, another Moody’s Economy.com official, told the Associated Press.

Mr. Right, with AAA Missouri, disagrees. “Paying 35, 50 cents more than this time last year. I doubt that’s going to affect noticeably on your holiday spending.”

So far, the recent increase in gas prices hasn’t affected St. Joe Distributing. Based in St. Joseph, its trucks deliver retail items to convenience stores in six states. Its flat delivery fee covers transportation, so no fuel surcharge is necessary.

“It’ll go up. It’ll go down. It averages out,” said President Brian Dickens. “But if it got up to four bucks again, I think we’d need a new plan.”

Ahmad Safi can be reached at ahmadsafi@npgco.com. The Associated Press contributed to this story.