ichael Zweig is professor of economics at the State University of New York at Stony Brook, where in 1999 he founded the Group for the Study of Working Class Life, an interdisciplinary center that studies the impact of class. Professor Zweig is also the author of "The Working Class Majority: America's Best Kept Secret" (Cornell University Press, 2000). Felicia R. Lee spoke with him.

How are you defining "class," and how does it differ from popular conceptions?

The common way that people talk in the popular culture and also in some sociology and other academic literature is to understand class as income. Or it's a matter of lifestyle: a person has class, they wear fancy clothes, they eat at good restaurants, they know which fork to use. I think those ways of looking at society are not very helpful. There are rich people, but to me, it's most helpful to understand class as power.

When I say middle class, what is it in the middle of? It's in the middle of labor and capital, not necessarily in the middle of income distribution.

Over the last 30 years, when the working class has been taking it in the neck, the middle class got divided. Those people in the middle class most closely associated in their lives and their work with the working class have done poorly. Those people in the middle class most closely associated with the capitalist class in their work have done very well. A Legal Aid attorney is much worse off now than 30 years ago. But the attorneys who are partners in white-shoe law firms, who are doing business with Wall Street, are doing very well.

You use the term working class; who exactly are you referring to?

Sixty-two percent of the labor force in the United States are working-class people, by which I mean people who do not have much control or authority over the pace or the content of the work and they're not a supervisor and they're not the boss. We're talking about white-collar workers, like bank clerks or cashiers; we're talking about blue-collar workers and construction and manufacturing.

How does income fit in?

If we're all in the middle class, then people think the poor will always be with us and there is something wrong with the poor. But if you look at the poor in any given year, it may be 12, 13 or 14 percent of the population but over a 10-year period, 40 percent of Americans experience poverty for at least one year.

The rich are really the top 1 percent. And they have more than half the wealth. The change in the distribution of income is widely known. I have some data from Business Week about the ratio of C.E.O. compensation to worker compensation. In 1981 it was 42 to 1; last year it was over 500 to 1, and it's gone up consistently.

Is there class mobility?

There is some, but not a great deal. The single most important predictor of a child's class position is the occupation of the child's parent. Not only for the working class but the middle class and the capitalists.

Do people confuse race and class?

The principal conflation of race and class comes from the idea that there's a broad middle class, and there's the rich and the poor. In that conception, this middle is really what Bill Clinton talked about, people who work hard and play by the rules. Who are these poor people? Well, they're black.

But two-thirds of all poor people in the United States are white, and three-quarters of all black people in the United States are not poor. We can't talk about the African-American community as one thing because it's divided by class.

You have people saying, "I don't want affirmative action for a black kid if their parents are professionals and their grandparents were professionals." White, working-class kids trying to get into college, trying to get a job are saying: "Why am I being disadvantaged for the child of black professionals? I want class-based affirmative action." Well, there's something to be said for that. But if you just do it on the economic status, you miss the continued existence of racism. It is complicated.

In your view, the increasing gap between the rich and the poor is not just a matter of real income but reflects the reduced power of workers.

The reduced power is in part the decline of union strength in the private sector and the weakness in organizational capacity of the labor movement, which now has less than 10 percent of the private sector in unions and about 13 percent of the total labor force, compared to the middle 1950's, when it was a third.

What is your take on this series of Wall Street scandals?

With the end of the cold war, the capitalist class is triumphant in that they just go to the limit. There is no organized opposition that is effective enough or strong enough to stop them. In the exercise of that power, it's extremely ugly. The mentality that cheats investors also cheats workers, like at Wal-Mart, where they don't pay workers for working off the clock.

What do you mean by organized opposition?

It would be a broad social movement that had different values, different ethics and different ways of understanding what is right and wrong and not a very narrow understanding of the bottom line.

How did Sept. 11 affect our notions of class?

There was a moment there when if you were your basic firefighter or emergency medical technician or ironworker, you were America's hero. I don't think the glow dissipated, but it's a question of how is that used, what are the lessons there. There is a double message: the workers are heroes but the workers didn't get help. Tens of thousands of people lost their jobs in the airlines but the workers did not get extensions of their benefits — but the airlines got $15 billion in aid.