TULSA, Okla. — School is out, and Aaron Stallings, his junior year of high school behind him, is in search of a job.

Stallings, 18, says he has been looking for months, burning gas to get to the mall, then filling out applications at stores selling T-shirts and baseball caps. He likes the idea of working amid the goods he covets. But so far, no offers.

“I’m going to go to Iraq and get a job,” he says acidly. “I hear they’ve got cheap gas.” He grins. “I’m just playing. But I’ve been all over, and nobody’s hiring.”

As the forces of an economic downturn ripple widely across the United States, the job market of 2008 is shaping up as the weakest in more than half a century for teenagers looking for summer work, according to labor economists, government data and companies that hire young people.

This deterioration is jeopardizing what many experts consider a crucial beginning stage of working life, one that gives young people experience and confidence along with pocket money.

Little more than one-third of the 16- to 19-year-olds in the United States are likely to be employed this summer, the smallest share since the government began tracking teenage work in 1948, according to a research paper published by the Center for Labor Market Studies at Northeastern University in Boston. That is a sharp drop from the 45 percent level of teenage employment reached in 2000.

The rates among minority young people have been particularly low, with only 21 percent of African-Americans and 31 percent of Hispanics from the ages of 16 to 19 employed last summer, according to the Labor Department.

Hiring pullback

Retailers, a major source of summer jobs, are grappling with a loss of American spending power, causing some to pull back in hiring. Restaurants, also big employers of teenagers, are adding jobs at a slower pace than in previous summers, said Hudson Riehle, senior vice president for research at the National Restaurant Association in Washington.

As older people stay in the work force longer, and as experienced workers lose jobs at factories and offices, settling for lower-paying work in restaurants and retail, some teenagers are being squeezed out.

“When you go into a recession, kids always get hit the hardest,” said Andrew Sum, an economist at the Center for Labor Market Studies who led the study on the summer job market. “Kids always go to the back of the hiring queue. Now, they find themselves with a lot of other people in line ahead of them.”

At the lower end of the market, adult Mexican immigrants, in particular, pose competition for jobs traditionally filled by younger Americans, like those at fast- food chains.

“Spanish-speaking team members in our stores have increased the age a little bit,” said Andy Lorenzen, senior manager for human resources at Chick-fil-A, a national chain of chicken restaurants based in Atlanta, where 70 percent of the work force is 14 to 19 years old. Adult workers “have lost jobs in this economic downturn and begun to seek employment in our stores.”

Employment among American teenagers has been sliding continuously for the last decade and, with a few ups and downs, dropping steadily since the late 1970s, when nearly half of all 16- to 19-year-olds had summer jobs.

Economists debate the cause of this precipitous decline in teenage employment. Many contend that the drop is largely a favorable trend, reflecting a rising percentage of teenagers completing high school and going on to college, with some enrolling in summer academic programs, leaving less time for work.

“The key factor is the attraction of attending college and enjoying the increasing wage premium that accompanies this,” said John Pencavel, a labor economist at Stanford University.

A waste of time?

In wealthier households, many have come to see summer work as a waste of time that could be spent gaining an edge in the competition for entry to elite colleges.

“Kids from higher-income households just aren’t going into the labor market,” said Mark Zandi, chief economist at Moody’s Economy.com. “They’re looking for things to put on resumes, and working at Dairy Queen or Wal-Mart just isn’t going to help you get into Wake Forest or Stanford. And they just don’t need the cash.”

But others, like Sum, contend that plenty of teenagers want to work but face increasing difficulties landing jobs. From early 2001 to the middle of 2007, the number of Americans employed outside the military grew more than 8.3 million, according to the Labor Department, yet employment among teenagers fell more than 1.2 million.

In the New York metropolitan area, an index by Economy.com shows a modest increase in the sorts of jobs typically filled by teenagers in the summer.

Still, with the economy gripped by what many experts believe is a recession, opportunities are growing leaner for teenagers in most of the country.

Even in parts of the country where there are jobs, some teenagers are having trouble finding them.

Tulsa, a town on the banks of the Arkansas River that swelled into a city amid an oil boom early last century, seems at first an easy place to find work. This metropolitan area of 900,000 people never saw the increase in housing prices and subsequent collapse that leveled economies elsewhere. While energy prices are reaching records and the oil patch is buzzing with activity, Tulsa’s unemployment rate was a mere 3.3 percent in March, compared with the national rate of 5.1 percent that month.

Here, the force of Hispanic immigration is being reversed: A bill aimed at cracking down on illegal immigrants passed by the state Legislature late last year has prompted thousands of them to leave town.

So, along the broad suburban avenues in the southern part of town — ribbons of black pavement lined with ice cream shops, burger stands and barbecue joints — managers are having a hard time finding workers.

“Pretty much everybody is hiring,” said Andy Irick, director of operations for Sonic, a restaurant chain based in Oklahoma, complete with blaring music and servers on roller skates. “If you walk in, and you’re clean-cut and presentable, you’re going to get a job.”

While summer jobs may be abundant in some industries, opportunities tend to divide along traditional fault lines like race, the connections offered by one’s parents and — not least — whether one has a car in this sprawling city of scant public transportation.