I won't give away (or bore you with) further details from the books, but the point is that, well, Krugman missed the point. For one thing, it's not 'social' scientists who collect and hold the galactic knowledge in trust: rather, the Foundation is a group of physical scientists whose task is to preserve the discoveries of physics, biology, chemistry, engineering, and other 'concrete' fields in order to accelerate the galaxy's climb back out of barbarism. As such, they don't truly save civilization; the Empire falls, and it's only by slowly re-introducing lost knowledge to the worlds around them that the Foundation is able to plants the seeds of resurrection. And, frequently, the Foundation succeeds only in spite of itself: some of its leaders try and 'game the game' by thinking they understand Seldon's plan and viewing themselves as the saviors of empire, whereas it's actually the individual decisions by audacious and independent actors (who more often than not do not occupy the seat of power) that move the plan along. For these actors, the grand plan of galactic salvation is secondary to finding practical solutions to current crises, and in the end it's their decisions that do far more to advance the plan than those of the plan's self-appointed handmaidens.
I'm also wary of those 'social scientists' throughout history who've seen it as their vocation to 'save' civilization. The twentieth century saw the development and result of various conscious experiments in social salvation, and those experiments, without exception, caused the greatest amount of suffering and bloodshed in recorded history. Eugenicists around the world were determined to save civilization from 'inferior' breeds, which included the poor, immigrants, the disabled, and anyone else who wasn't 'useful' to society. This resulted in everything from forced sterilization in the United States to the widespread extermination of Jews, gypsies, 'non-Aryans', homosexuals, Christians, and the mentally and physically handicapped in Nazi Germany. Communists wanted to save the world from the evils of capitalism: the world is still absorbing the swath of suffering and oppression that spread from the gulags of Russia to China's 'Great Leap Forward' to the killing fields of Cambodia, and still exists in backwaters from North Korea to Cuba. The last hundred years have witnessed many variations on the theme of social salvation, and while the 'science' used to justify each method differed, the result was the same: destruction and death on an unimaginable scale. Social engineering, without fail, has become the province of tyrants and butchers, no small number of whom started with the best of intentions.
Far more often, we find civilization's saints hidden in obscurity, working on their own toward humble goals with no thought of re-creating the world in their own image. It was the monk, not the king, who preserved the ancient world's treasures in humble monastaries during the Dark Ages; the renaissance tinkerer, not the tyrant, whose curiosity laid the groundwork for everything from modern industry to medicine; the modern enterpreneur, not the president, who gave us the technological breakthroughs of the Information Age. That's not to say that the king or tyrant didn't have their place, but they best served civilization's interests by providing things like resources or patronage and then staying out of the way while allowing the human mind to explore the multitude of pathways a single leader can't imagine on his own. Those individuals who've seen themselves as saviors tend, rather, to stifle the many small acts of salvation and improvement that individuals, acting on their own with less grandious ambitions, generate.
I do not doubt Krugman's good intentions, or question his intelligence; but I think his burning desire to be civilization's savior should automatically disqualify him for the job. That, and he needs to re-read his Asimov.