" About every two generations—roughly every forty-seven to sixty years—there’s a deflationary market. For example, in respect to the commodity markets, we’re currently in a deflationary phase that began in 1980. Over the past two hundred years, these deflationary phases have typically lasted between eight and twelve years. Since we’re currently in the twelfth year of commodity price deflation, I think we’re very close to a major bottom in commodity prices. "

― Jack D. Schwager , The New Market Wizards: Conversations with America's Top Traders