Krugman addresses the question about the collapsing ruble in December 2014- why the extent of the collapse reflected more than the drop in oil prices? He focusses on the nature of the Russian system under Putin which is based on crony capitalism. Russian businesses borrowed heavily in dollars but generate much of their revenue in rubles, as a result the situation has imploded with the inability of these businesses to make payments as the ruble declined by about 50%. Russia has not generated trade deficits. Capital flight, money taken out of the country by oligarchs, and the nature of the borrowing in foreign currency has led to a serious compounding of the crisis.