was a hole the size of the Grand Canyon", in the analysis. O'Rourke also referenced the PricewaterhouseCoopers/World Bank survey that Ireland's ETR was circa 12%. In December 2014, the Irish Department of Finance, gathered a panel of Irish experts (but no international experts) to estimate Irish corporate ETR for the Committee on Finance Public Expenditure. The results, summarised on Section 2 (page 13) of the report, showed all of the Irish experts, with the exception of Dr. Jim Stewart, agreed with Feargal O'Rourke and PricewaterhouseCoopers: 11.1% Prof. Frank Barry Trinity College Dublin (using Devereaux methodology) 14.4% Mr. Gary Tobin Department of Finance (using European Commission/ZEW data) 12.5% Mr. Eamonn O'Dea Revenue Commissioners (using Irish Revenue Statistical Data) 12.4% Mr. Conor O'Brien KPMG (Ireland) (using Irish Revenue Statistical Data) 2.2% to 3.8% Prof. Jim Stewart Trinity College Dublin (using U.S. BEA Data) In August 2016, when the EU Commission published the results of their 2–year detailed investigation of Apple's tax structure in Ireland (see above), showing that Apple's ETR in 2014 was 0.005%, the Irish Revenue Commissioners stated that they: "had collected the full amount of tax that was due from Apple in accordance with the Irish law". In December 2017, the Department of Finance published a report they commissioned on the Irish corporate tax code by UCC economist, Seamus Coffey. The report estimated that Ireland's effective corporation tax rate for 2015 was 7.2%, based on the Net Operating Surplus Method (which accepts IP BEPS flows as tax deductible costs); and had fallen from 11.2% in 2008 (section 9.4 page 128). Corporate tax inversions Background An Irish corporate tax inversion is a strategy in which a foreign multinational corporation acquires or merges with an Irish–based company, then shifts its legal place of incorporation to Ireland to avail itself of Ireland's favourable corporate tax regime. The multinational's majority ownership, effective headquarters and executive management remain in its home jurisdiction. Ireland's corporate tax code has a holding company regime that enables the foreign multinational's new Irish–based legal headquarters, to gain full Irish tax-relief on Irish withholding taxes and payment of dividends from Ireland. Almost all tax inversions to Ireland have come from the US, and to a lesser degree, the UK (see below). The first US tax inversions to Ireland were Ingersoll Rand and Accenture 2009. As of November 2018, Ireland was the destination for the largest US corporate tax inversion in history,