The questions now to be answered are how much wheat will Russia export by the end of January and how much of the world's 2014/15 wheat demand, which it potentially might have filled thereafter, must be shifted to other origins.Russia's announcement during the Christmas holiday that it would begin imposing a tax on wheat exports starting 1 February came as no surprise. For three weeks or more, world wheat traders had been expecting the Russian government to intervene in some way to limit those exports. The plunging value of the ruble versus the U.S. dollar and strong demand from exporters were pushing internal wheat values priced in rubles sharply higher. Even though FOB export values for Russian wheat priced in U.S. dollars remained fairly...