If the American dream means doing better than your parents did, then Mike Brockman's not living it. Single, with a 10-year-old daughter, he's a server at a Black Angus restaurant in Mesa, Ariz. His father at his age had a good, steady job as a machinist at TRW.

Today "there aren't the kind of jobs available you used to get with a high school education, and work yourself up," says Mr. Brockman. "Now you have to have training or experience to start – then you can work your way up from there."

Norman Payne, on the other hand, thinks the American dream is alive and well. An immigrant from Panama, he's lived in the US for 16 years – and on June 28 in Boston he was sworn in as a US citizen.

Mr. Payne works in customer service at Kodak and has high hopes for his young son and daughter.

"I don't think the American dream has changed," he says. "I am trying to do everything I can do so that they can do better than I did."

Two hundred and thirty-one years after the 13 colonies declared their independence from Great Britain, is the United States still the land of opportunity, the light of hope for the poor of the world?

The economic dream that has united a diverse population for generations, that children would be more prosperous than their parents, is in question as perhaps never before.

Yet the nation's overall standard of living remains high. Immigrants both legal and illegal arrive every year by the tens of thousands, testament to the US economy's continuing dynamism.

Less mobility in US

Overall, there is actually less economic mobility in the US than in Canada and many European countries, notes John Morton, Managing Director, Program Planning and Economic Policy, for the Pew Charitable Trusts.

But for immigrants "the economic assimilation machine is in fact still very strong," says Mr. Morton, who is helping lead a long-term Pew project on the American dream's health.

The phrase "American dream" is relatively recent. It was popularized in the 1930s by historian James Truslow Adams, who in his day was a widely read author on the major themes and figures of the nation, similar to, say, David McCullough today.

Yet the idea expressed by the phrase, that the US was a land of opportunity where generation after generation would keep doing better and better, has always been the "gyroscope of American life," writes Southern Methodist University political scientist Cal Jillson in his book "Pursuing the American Dream."

In some periods the American dream has seemed more attainable than in others, says Mr. Jillson. Most recently, it was alive and well in the era from the end of World War II through the early 1970s.

But since 1973, median family income has been essentially flat, says Jillson.

"This is one of those periods in American history when to many ... the American dream seems illusory," Jillson says.

Some polls back up this contention. In a recent CBS News survey of 17- to 29-year-olds, only 25 percent of respondents said their generation would be better off than their parents. Forty-eight percent said they would be worse off.

The American dream is "obsolete," says Adam Gandelman, a Boston bike messenger. "It's a scam."

Single-earner families see fall in pay

Income figures show that the days are gone when a single, stable income, typically earned by the father, was enough to launch the next generation to greater prosperity, according to a Pew report on economic mobility released this spring.

Today, men in their 30s earn about $5,000 less in real terms than did their fathers' generation, according to Pew.

That fits with Brockman's experience. Neither he, nor his father, graduated from college. Nor did his grandmother, but she worked her way up from a secretarial position to the executive ranks at GE.

"I couldn't get the job my dad had at [age] 30 without a degree, or waiting in line for years," he says.

However, overall family income is a different story. Families with men in their 30s today have about $4,000 more in annual income than did their parents' generation.

"The main reason that family incomes have risen is that more women have gone to work, buttressing the incomes of men by adding a second earner," notes the Pew economic mobility report.

Katy Curtis, a real estate agent in north Scottsdale, Ariz., did not work when she was in the family-rearing stage of life. "And we survived quite well," she says.

But her two daughters, now in that thirty-something cohort, are finding life economically more difficult, she says.

They see new cars and plasma TVs and other accoutrements everywhere, and they want them, too. "I think there are more demands made upon them materialistically, and it's harder," says Ms. Curtis. "Things have gone up in price, and I don't think salaries are commensurate with that."

Some experts point out that income measures today are an inexact gauge of family well-being.

Cash, for example, is just one part of compensation. "Total compensation includes such increasingly important components of workers‚ pay as health benefits, contributions to retirement plans, and paid vacations," writes Heritage Foundation labor expert James Sherk in a recent analysis of economic mobility.

And the use of the Consumer Price Index to calculate inflation-adjusted pay is a mistake, according to Mr. Sherk. Economists should use the more accurate implicit price deflator instead.

"The result of this mistake is that wage growth will almost always appear to lag far behind productivity growth, even when workers are making gains," writes Sherk.

Nor does everyone judge the American dream to be purely based on monetary gain.

Mike Heitmann is a Kansas City resident visiting his wife's family in Boston, his four daughters in tow. "The American dream is having a strong family and living in a place where we have freedoms like we do in the US," says Mr. Heitmann. "Family is the most important thing."

More to American dream than money

Wallace Sheppard will return to Iraq for his third tour there in October. The Army serviceman, based in Ft. Campbell, Kentucky, is also in Boston as a tourist.

"I define [the American dream] as being happy," he says. "Money doesn't really mater if you make enough to sustain your family."

And for the masses in many other parts of the world, whether they are huddled or not, the Statue of Liberty still stands as their dream destination.

Joseph Nemorin today is a line cook at Nick's Italian Restaurant on Ocean Drive in Fort Lauderdale, Fla. He's been there 17 years.

He arrived in the US from Haiti when he himself was 17. Today he is a legal permanent resident who says he has done better than his parents. He expects his children will do better than he has, because they were born in America.

The American dream is available for those who come to the US for the right reason, he says. "If you come to work, you don't get in trouble ... you should be doing fine, just like me."

Faye Bowers in Phoenix, Bill Frogameni in Fort Lauderdale, Fla., and Bina Venkataraman in Boston contributed to this report.