I don’t know what the motive would have been, though, other than what Roosevelt said it was. There would have been no reason for the government to own all the gold but the reason they gave. On the other hand, their strategy ultimately did not work. They still did not increase the money supply fast enough, and ultimately, they began to buy silver as well, and even that was not enough.
The biggest mistake that the New Dealers made was in assuming that they could stimulate the economy by manipulate the price structure, particularly the wage structure. It’s pure nonsense. All you do is cause inefficiency. It has no positive macroeconomic effect. To some degree, Obama is making the same mistake.