Back in the 1970s, the spike in oil prices caused a general rise in prices that was at the time considered 'inflation.' Looking back, economist now know that a supply shock the spikes relative demand is NOT the same as inflation. Instead, inflation is always a monetary phenomenon.
Based on this erroneous read of prices, the Fed raised interest rates when it should have lowered them. The result of this error was the throttling of the economy that produced stagnation AND we still had high 'inflation.'
Fast forward to today. The crashing of oil prices is send the stock market downward, and creating a general downward trend on prices. The Fed is about to confuse this with deflation. Yes, the Fed believes that after printing 85 billion dollars a month for several months, we are about to experience deflation.
That wrongheaded reading will cause the Fed to forestall raising interest rates when it should, producing a very real risk of REAL INflation in the coming years because of super easy money for far, far too long.