Predictive relationships appear to occur between large, rapid swings in oil price and recessions, stock market crashes and shifts in political polls, as I have previously discussed in articles published in 2010 and 2011 . Given the economic disruptions that nearly always happen in the aftermath of oil shocks, it seems important to understand what is behind the timing of transient instabilities in the oil markets. Last time, I examined whether repetitive patterns could be found in the ebb and flow of oil price changeability (volatility) between 2000 and 2010. To do this, I calculated rolling standard deviations (for explanation, please see Figure 2 in this post ) for a 120-month series of monthly oil prices starting from January 2000. A mathematical tool called Fast Fourier Transform then scanned for repeating patterns in this rolling 10-year sequence. What I found was that from the mid-2000s, changes in oil price […]