Of course, Sarah Palin is quite right in her concerns about the economic impact of more quantitative easing.  At best, Ben Bernanke’s efforts may add a third of percentage point to GDP. Maybe. And at what cost? Bubbles in commodities and emerging markets, capital controls, currency interventions, further erosion of America’s role as an economic model. All for, as Palin puts it, “temporary, artificial economic growth.”   Or as Kevin Warsh of the Fed puts it: