 Tax academics show multinationals from countries with "territorial" tax systems make little use of tax havens like Ireland.Since the UK changed its tax regime to a "territorial" system in 2009–12, Ireland has failed to attract corporates from any other jurisdiction except the US, one of the last "worldwide" tax systems.By September 2018, US–controlled corporates were 25 of Ireland's 50 largest companies, paid 80% of Irish business taxes, and directly employed 25% of the Irish labour force, and created 57% of Irish value-add.