BufGlobal currency devaluation efforts will fail in the absence of economic policies that foster growth, said Slim, 70, in an interview in New York on Oct. 29.

"The best way to have a healthy fiscal environment is that investment should be done by the private sector," Slim said. Currency devaluations "will not succeed in any way and they will pressure commodities," he said.fett, ranked the third-richest man by Forbes, said in a June 2009 Bloomberg Television interview that the U.S. may need a second economic stimulus package to combat rising unemployment. In his annual letter to investors issued in March 2009, Buffett also said "major industries have become dependent on federal assistance and they will be followed by cities and states bearing mind-boggling requests."

Gates, the co-founder of Microsoft Corp., called Obama's economic stimulus package "essential" in a December 2008 speech at George Washington University in Washington. "Spending is the only way to get out of this downturn," Gates said.

Currency devaluation efforts with high commodities prices are a danger, said Slim. "If currencies go down and the commodities stay up, there will be a big problem for the population," increasing food prices and sparking inflation, he said.