Inward investment is transient - Home economy

The reason is that the United States Treasury has introduced rules to curb so-called ‘inversion’ deals that, up to now, allowed major industries cut their tax bills by setting up shop abroad. The merger would have allowed New York-based Pfizer to cut its tax bill by relocating its HQ to Ireland.
Ireland has for years been a favoured destination for big US companies because of low corporation taxes, and we should not kid ourselves that it is because of our highly educated population and EU membership, though these factors help.