The retreat has kindled fears that foreign firms, many of which moved to Ireland largely for its tax policies, will leave for more accommodating climes. (As it is, a clampdown on avoidance in America seems to have deterred AbbVie, a drugs firm, from taking over Shire, a rival based in Ireland.) Yet the government is giving with one hand even as it takes with the other. On the same day it did away with the Double Irish, it created a “knowledge development box”, which will allow firms to pay a lower tax rate on profits from intellectual property booked in Ireland. The OECD has tried, unsuccessfully, to limit this type of tax benefit, which is also known as a “patent box”. Moreover, the Double Irish won’t die overnight. Companies already registered in Ireland are being given six years to alter their accounting structures.