I wonder how much Irelands payroll taxes would have been were the corporations not to have set up shop in Ireland, they would have just gone somewhere with a decent tax arrangement.
Unemployment in the 70's and 80's was brutal in Ireland, personally, I think the government at the time made the right choice, however, this "selective treatment" allowed Apple to pay tax rate of 1% on European Union profits in 2003 down to 0.005% in 2014, FFS.