estimates Ireland's effective tax rate is really 4%. The U.K. is a notable absence. (slide 68). CORPNET Corporate tax havens From the 2017 investigation, published in Nature, into Conduit and Sink OFCs, comes CORPNET's top 5 Conduit OFCs (i.e. corporate tax haven proxy), and top 5 Sink OFCs (i.e. traditional tax haven proxy), as calculated by analysing over 71 million global corporate connections on the Orbis database (i.e. it is by number of connections, not specifically by quantum of taxes shielded). Even though the method is different, CORPNET captures all of Zucman's list but separated into Conduits and Sinks (and breaks out the Caribbean), however, Zucman's list has a different ranking: Conduit OFCs (by the number of corporate connections), 2017: Sink OFCs (by the number of corporate connections), 2017: ITEP Corporate tax havens The first Institute on Taxation and Economic Policy list (Figure 1, page 11), is based on the % of Fortune 500 companies with subsidiaries in the corporate tax haven in 2016. The drawback of the list is that it is a U.S. focused list, and focuses on the number of connections (i.e. or subsidiaries) rather than the scale of taxes shielded. Contains all of Zucman's list, but with Mauritius and Panama added as well. Percentage of Fortune 500 companies with subsidiaries in the jurisdiction, 2016: The second Institute on Taxation and Economic Policy list (Figure 4, page 16), is based on the reported profits of U.S. Fortune 500 controlled subsidiaries in 2013. It tries to capture the scale of taxes shielded by looking at reported profits as a proxy. Ireland now jumps to 2nd place, only just behind the Netherlands. The Netherlands-Ireland-Bermuda are usually the jurisdictions behind most "double Irish with a Dutch sandwich" BEPS schemes. Identical list to Zucman's list but with the Caribbean broken out into individual jurisdictions (the Caymans, Bermuda, Bahamas and the BVI). Size of profits routed by Fortune 500 companies via subsidiaries in the jurisdiction, 2016: Bloomberg Corporate tax inversions A simple but effective proxy are the destinations to where U.S. multinationals execute tax inversions (i.e. an important test of the attractiveness of a corporate tax haven). However, cases like inversions to Canada could reflect more of a "relative-tax" view (i.e. Canada offers lower taxes than the U.S. and it is close by and less controversial), than an "absolute-tax" view on the best global locations for a corporate tax haven. The list