The United Kingdom has a drinking problem. British per-capita consumption of alcohol rose $19 \%$ between 1980 and $2007,$ compared with a $13 \%$ decline in other developed countries. Worried about excessive drinking among young people, the British government increased the tax on beer by $42 \%$ from 2008 to $2012 .$ Under what conditions will this specific tax substantially reduce the equilibrium quantity of alcohol? Answer in terms of the elasticities of the demand and supply curves.