Bill Gross, who runs the world's biggest bond fund, said on Wednesday that greed will make a comeback among consumers and investors but cautioned it may well take at least one generation to unfold.

Greed will come again. But for now, the trend is the other way and it promises to persist for a generation at a minimum, said Gross, the co-chief investment officer of Pacific Investment Management Co., or PIMCO, and manager of the Pimco Total Return Fund, which has $154 billion in assets.

The supersizing of financial leverage and consumer spending in concert with the politicizing of deregulation describes in fifteen words our most recent brush with irrational behavior and inefficient markets, Gross said in his monthly newsletter to clients, posted on www.pimco.com.

American consumers have suffered a collapse in wealth of at least $15 trillion since early 2007, Gross noted. That will have an impact on consumption patterns, he added.

When potential spenders feel less rich by that much, the only model one can use to forecast the future is a commonsensical one prompting higher savings and lower consumption.

Under this scenario, he saw a U.S. economic growth rate as the new normal closer to 2 percent as opposed to 3.5 percent.

There's no magic in that number, and no model to back it up, just a lot of common sense that says this is how people and economic societies behave when stressed and stretched to a near breaking point, Gross added.

(Reporting by Jennifer Ablan; Editing by Theodore d'Afflisio)