Like any major intellectual contribution, Keynes's ideas were bitterly criticized. To many people it seems obvious that massive economic slumps must … - Paul Krugman

In a way, the worst sin of the conservatives was that of hypocrisy. They proclaimed growth as their objective, offered it as the answer to all problems, all while following policies that actually inhibited that growth at least a bit. At the end of the day, however, the most striking fact is how little happened to U.S. long-term growth, good or bad, on their watch.

As is often the case with major disputes in economics, the argument over fiscal policy went on for years, with some critics of fiscal policy still defending their position when this book went to press. It seems fair, however, to say that among economists a more or less Keynesian view of the effects of fiscal policy came to prevail. Careful statistical studies at the International Monetary Fund and else where showed that austerity policies have historically been followed by contraction, not expansion. Recent experience, in which countries like Spain and Greece that were forced into severe austerity also experienced severe slumps, seemed to confirm that observation. Furthermore, it was clear that those who had predicted a sharp rise in U.S. interest rates due to budget deficits, leading to conventional crowding out, had been wrong: U.S. long-term interest rates remained near record lows even during the years from 2009 to 2012, when the government ran very large deficits.

… politics determine who has the power, not who has the truth.