Russia's growth is negative, their unemployment is rising, and their bonds are rated as junk. Their economy was fueled by high oil and gas prices and not because of their flat tax. When prices for those took a dive their economy went down with it.
Russia is much stronger economically than under the Soviet regime. WHy did’nt teh USSR do well with all that oil and gas? The point is, Russia has adopted capitalistic economy. Our tour guide in French Riviera pointed out all the best properties have been bought up by Russians. What is hampering Russia is NOT flat tax, it is Putin with his KGB mentality.