Why commodity prices are down in US but up in Europe

Why commodity prices are down in US but up in Europe. Jeffrey Frankel, December 31, 2014, Opinion. "OIL prices plummeted 43 per cent during the course of 2014 - good news for oil-importing countries, but bad news for Russia, Nigeria, Venezuela and other oil exporters. Some attribute the price drop to the US shale-energy boom. Others cite Opec's (Organization of the Petroleum Exporting Countries) failure to agree on supply restrictions. But that is not the whole story..." May require purchase or user account. Link