I start (and started) from the premise that the
dramatic decline in crude oil
prices that took place from August, 2014 ($ 96 / barrel), to March, 2015 ($ 44 / barrel), was due — on the one hand — to
decreased demand, a function of slow economic growth in Asia, Europe, and elsewhere, endogenous,
price - driven technological change leading to greater fuel efficiency, and policy - driven technological change that also has been leading to greater fuel efficiency, such as more stringent Corporate Average Fuel Economy (CAFE) standards in the United States; and — on the other hand — was due to increased supply, partly a function of the growth of unconventional (tight) U.S. oil production (a product of the combination of two technologies — horizontal drilling and hydraulic fracturing).