The study, however, did not look at whether wages were affected by immigration. Advocates for tighter immigration policies argue that immigrant workers depress wages for American workers, especially those with few skills and little education.

Immigration supporters argue that foreign workers often take jobs that Americans don't want and won't take.

The Pew Hispanic Center is a nonpartisan research organization that does not advocate policy positions. The center studied census data on the increase in immigrants from 1990 to 2000, and from 2000 to 2004, for each state. It matched those figures with state employment rates, unemployment rates and participation in the labor force among native-born Americans.

The U.S. had 28 million immigrants - legal and illegal - age 16 and older in 2000, an increase of 61 percent from 1990. By 2004, there were 32 million.

Among the study's findings:

- Twenty-two states had immigration levels above the national average from 1990 to 2000. Among them, 14 had employment rates for native-born workers above the national average in 2000, and eight had employment rates below the national average.

- Twenty-eight states and the District of Columbia had immigration levels below the national average from 1990 to 2000. Among them, 16 had above average employment rates for native-born workers in 2000, and 13 had below average employment rates.

- Twenty-four states had immigration levels above the national average from 2000 to 2004. Among them, 13 states had employment rates for native-born Americans above the national average in 2004, and 11 had employment rates below the national average.

- Twenty-six states and the District of Columbia had immigration levels below the national average from 2000 to 2004. Among them, 12 had employment rates for native-born Americans above the national average, and 15 had employment rates below the national average.

Immigrants tend to be younger and have less education than American workers. The study, however, found "no apparent relationship between the growth of foreign workers with less education and the employment outcome of native workers with the same low level of education."

However, Steven Camarota, director of research for the Center for Immigration Studies, said his research shows that many young workers with little education are hurt by competition from immigrants.

"Employment for less educated natives has declined, and their wages have declined," said Camarota, who advocates stricter immigration policies. "There is no shortage of less educated workers in the United States."

"I don't think it will be felt at all," said Jay Bryson, global economist at Wachovia Corp. in Charlotte, North Carolina. "Think back to last year -- the (London) Underground bombings had little impact. Unless it happens on our own soil, it will probably have no impact at all."

Stocks took the news in stride, with all three major U.S. indexes rising on the day.

"I talked to a lot of clients and traders about this and one thing I came away with was that this, believe it or not, is encouraging in that UK intelligence foiled this plot," said Anthony Chan, chief economist at JPMorgan Private Client Services in New York. "You have to come away with some optimism out of this craziness."

Declines were scattered in the travel and tourism industry with Continental Airlines ending more than 1 percent lower, while AMR Corp., the parent company of American Airlines, scrapped its way back to even after being down as much as 4 percent. Shares of major hotel chains like Hilton and Starwood both fell around 2 percent, but Four Seasons Hotels Inc. shot up more than 3 percent.

"It does tend to chill the travel industry and tourism -- (but) it tends to be a short-term chill," said Brian Bethune, U.S. economist at Global Insight in Boston.

Economists can now rely on data from the months following September 11, 2001, as a benchmark for the broader economic effects of any attack -- thwarted or otherwise.

Wayne Wicker, chief investment officer for the Vantagepoint Funds in Washington D.C., said it could hurt the airline and hospitality sectors if tougher security measures cause people to cut back on discretionary travel. If that happens, it would be another factor in an economy where growth is already slowing, he said.

Since economists were already expecting consumer-driven growth to take a backseat to business spending in 2006, they anticipated industries such as travel, lodging, apparel and restaurants would begin to weaken anyway.

For many economists, the real wild card looming over the U.S. economy is a further spike in oil prices. In fact, news of the bomb plot actually drove oil prices lower, underpinning the positive tone on the stock market.

Still, the fact that crude fell more than 3 percent on Thursday shows oil traders weren't as sanguine about the news and the prospects for the economy. Front-month crude futures fell $2.35 to $74 a barrel on worries that heightened fear of air travel would hurt consumer confidence and damp growth.

"This is just one more reason for consumers to be nervous and to cocoon themselves," said David Wyss, chief economist at Standard & Poor's in New York. "But since most voluntary air travel, as opposed to business travel, is booked well in advance it will be a while before we see the impact."

London Brent crude climbed 30 cents to $75.58, about $3.00 below the record high touched on Tuesday.

The suspected plot raised the specter of strikes to rival the September 11, 2001 attacks on the United States that killed about 3,000 people and came 13 months after four British Muslim suicide bombers killed 52 people on London's transport network.

U.S. unleaded gasoline futures settled at below $2.00 per gallon for the first time since June 21 on Thursday, before recovering 1.89 cents to $2.0439 on Friday.

Fears of a prolonged outage at Alaska's Prudhoe Bay oilfield continued to support prices. While the U.S. government on Thursday appeared to allow BP to keep oil flowing from the western half of the development, the major has said it will decide only next week whether to do so.

"The Alaskan situation is still not totally clear and then we have all of the other bullish geopolitical risks," Tony Nunan, Assistant Manager of Risk Management at Mitsubishi Corp, said, referring to the overnight fall factors in crude.

BP WESTERN LINE HOPES

BP began shutting the 400,000 barrel-per-day (bpd) Prudhoe Bay oilfield, which accounts for 8 percent of U.S. production, on Sunday due to a corroded pipe, but has been working to keep some output flowing from the west, where damage is less severe.

The U.S. Transportation Department's Pipeline Hazardous Materials Safety Administration (PHMSA) on Thursday laid out new requirements for restarting BP's halted eastern pipeline, but also suggested that the company -- which had voluntarily moved to halt production -- would be allowed to use its Western line.

"The order also directs BP to strip the insulation from its Western operating line, which may continue to move oil, and conduct an ultrasonic test... to obtain a complete picture of the line's conditions," it quoted PHMSA Administrator Admiral Thomas Barrett as saying in a statement.

The replacement of corroded pipelines at the oilfield is expected to cost around $100 million, a BP source said, although the total cost to BP will likely be several times this figure.

The market also lost ground on Thursday after Royal Dutch Shell said it had repaired a pipeline in Nigeria shut since last month, allowing 180,000 bpd of shut Bonny Light oil production to start to resume.

Oil traders are also watching for any progress toward ending the four-week fighting between Israel and Hizbollah in Lebanon after key U.N. Security Council members had failed to reach a resolution, prompting Russia to propose a 72-hour truce.

Diplomats said a deal was possible by the end of Friday.

Hizbollah guerrillas fought Israeli troops who seized a key town in southeast Lebanon on Thursday, while Israel said plans for a deeper ground assault into southern Lebanon were on hold to give diplomacy a chance.

Over 2.48 billion dollars will be used in strengthening the fledgling Afghan National Police and Afghan National Army, it said.

A total of 587 million dollars will be available for reconstruction, 73 million for democracy and governance and 120 million for humanitarian and other assistance, the statement added.

Washington has been the major backer of Afghanistan's fledgling government since a US-led coalition toppled the Taliban regime nearly five years ago following the September 11, 2001 attacks.

But Kabul along with NATO and US-led forces is battling an escalating insurgency led by the fundamentalist Taliban, which has this year claimed more than 1,000 lives -- most of them militants.

US ambassador Ronald Neumann, said recently that American efforts would now focus on southern Afghanistan, saying that his country was more or less the only one able to work there.

Insurgents, drug traffickers and local warlords make the security situation in the south extremely precarious, with aid workers coming under intermittent attack.

Exports rose 11.5 percent in the year to June, while imports increased 11.3 percent. In June French exports were worth EUR 32.9 trillion and its imports 35.5 trillion.

The most dynamic area, both for imports and exports, was the industrial sector. In addition to delivering two dozen Airbus planes in June, France sold a ship to Panama for EUR 420 million and two satellites - to Kazakhstan and the United States - for more than 200 million. It bought two Boeing aircraft and a satellite.

But a rise in energy imports due to strong domestic demand weighed heavily on the trade balance, due to the high price of oil. The bill for imports of crude - most of it from Iran - rose by EUR 400 million in June to EUR 4.2 trillion.

Junior Trade Minister Christine Lagarde insisted on RTL radio: "The trade deficit is narrowing". She said France was refocusing exports on "high-growth areas" and its foreign trade had been "distinctly better" in the first half of 2006 than in the first six months of 2005.

Nicolas Bouzou, economist with forecaster Asteres, said the latest trade figures were an indication of France's "lack of dynamism and dependence on the economic recovery in Germany and the euro zone".

He stressed that the difficulties facing the French vehicle manufacturing sector had become "structural".