The price of oil in global markets has plunged by nearly 45 percent over the past six months. As a result, the price of a gallon of regular gasoline in the U.S. dropped from $3.68 in June to $2.37 in late December. In June, the U.S. Energy Information Administration had projected that a gallon of gas would average $3.48 per gallon in the second half of 2014. What happened?, asks Ron Bailey. And where might oil prices go in the next two to five years?