Could Diminshing Returns be a reason the US economy fails to correct itself from its disequilibrium problem, a growing deficit problem, disinflation problem, currency devaultion problem, higher tax burden problem, dislocated worker problem, worker expecting instant gratification problem, a divide nation problem, etc...?

The more you have, the smaller is the extra benefit you get from having even more. For instance, when workers have a lot of CAPITAL giving them a little more may not increase their PRODUCTIVITY anywhere near as much as would giving the same amount to workers who currently have little or no capital. This underpins the CATCH-UP EFFECT, whereby there is (supposedly) convergence between the rates of GROWTH of DEVELOPING COUNTRIES and developed ones.

Ya'll better have something of worth to trade with the rest of the globe!