"After six months of declining oil prices, we suddenly got plunging oil prices. Why? Not so much because of the shale oil revolution in the US. For all the attention it gets, fracking has increased global oil production by only a few percent and would normally have only a moderate effect on prices. Unfortunately, these aren't normal times: in addition to a small increase in the oil supply, the global economic slowdown has depressed demand. That's a bigger factor than fracking, and with European and Asian economies looking increasingly fragile, not one that seems likely to be corrected anytime soon."