Pfizer’s $106.4 billion buyout offer of British pharmaceutical giant AstraZeneca is being largely driven by high US corporate taxes. At yearend 2013, Pfizer had $70 billion of overseas earnings that, if repatriated, would result in huge US taxes. Buying AstraZeneca with the overseas earnings eliminates the tax bill on the $70 billion and moving the merged firm’s headquarters from here to the lightly taxed UK reduces taxes on future earnings.