For more than a century, Russia has suffered periodic waves of mass emigration. Now it could face yet another one, perhaps leading to the largest brain drain the country has experienced in 20 years. According to Russia's state statistical agency, 350,000 people emigrated from Russia in 2015 -- 10 times higher than it was five years ago. The outflow began in earnest in 2012, mostly driven by political friction in the country, but Russia's current economic crisis has accelerated the pace. The Kremlin is attempting to curb the so-called suitcase mood, but other national interests remain a higher priority. As highly skilled Russians emigrate, the future of innovation and private business in the country has been called into question. Meanwhile, migrants from mostly Muslim former Soviet states are entering Russia in search of work, altering the ethnic and religious composition of the population and heightening tension in the process....