I wouldn't think it was the EU subsidies; I would think it's partly the tax. The other big thing, as Professor Brooks said, was the fact that Ireland joined the European Union, and thus it was a location in which firms could establish themselves and have access to the whole of the EU market. That happened at very much the same time, so it's very difficult to disentangle the two.
On April 14th, 2008. See this statement in context.