Yesterday Nicholas Kristoff trolled professors, and especially political scientists, crying out: “Professors, we need you!” Naturally, it echoed about the web (e.g., here), and kicked up a counter-response from bloggers noting that they exist (e.g., here and here).
What strikes me as missing from the discussion is consideration of the temporal process for knowledge diffusion. As I am incapable of making the case better than John Maynard Keynes did when addressing this very point in 1936, I leave it to him:
the ideas of economists and political philosophers, both when they are right and when they are wrong, are more powerful than is commonly understood. Indeed the world is ruled by little else. Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually the slaves of some defunct economist. Madmen in authority, who hear voices in the air, are distilling their frenzy from some academic scribbler of a few years back. I am sure that the power of vested interests is vastly exaggerated compared with the gradual encroachment of ideas. Not, indeed, immediately, but after a certain interval; for in the field of economic and political philosophy there are not many who are influenced by new theories after they are twenty-five or thirty years of age, so that the ideas which civil servants and politicians and even agitators apply to current events are not likely to be the newest. But, soon or late, it is ideas, not vested interests, which are dangerous for good or evil.
It is not in Mr Kristoff’s interest to consider Keynes’ point, but it is one that Professors do well to keep in mind: ideas take root when the young people who learn them assume positions of power, usually a decade or more later. #GenerationalLagStructure
 From (1936) The General Theory of Employment, Interest and Money, chapter 24.