In the Kondratiev waves and other commonly cited cycles -- the Kitchin (three to five years), the Kuznets (fifteen to twenty years) -- the time span is flexible. They are suggestions, not rules. Hard-core cyclists, on the other hand, often seek and find instances of periodicity as rigid and fixed as the laws of physics, which is why hardcore cyclists are often dismissed as mystics or freaks.And
We tend to ascribe rising markets and an expanding economy, as long as they last, to our own ingenuity -- to progress, experience, rationality, a generational refinement in the ability of economists and central bankers to manage our affairs. Bull markets are seen to be incarnations of human perfectibility. (Home prices would rise forever, because we had invented a new kind of debt, one that didn't ever have to be repaid.) When things go to pieces, we shirk responsibility and seek other explanations. Fatalism creeps in. It can't be merely that we are, as ever, greedy, short-sighted creatures, prone to self-delusion, incapable of learning from the past. There must be something, or Something, else at work, beyond our understanding or control.