" It is one thing when prices drift downward over time due to innovation, scalability or other efficiencies. This might be considered “good” deflation and is familiar to any contemporary consumer who has seen prices of computers or wide-screen TVs fall year after year. It is another matter when prices are forced down by unnecessary monetary contraction, credit constraints, deleveraging, business failures, bankruptcies and mass unemployment. This may be considered “bad” deflation. This bad deflation was exactly what was required in order to return the most important currencies to their prewar parity with gold. "

― James Rickards , Currency Wars: The Making of the Next Global Crisis