The Economist has this on Ireland's role as the global hub for aircraft leasing,
Previously, airlines owned all their aircraft. Leasing allows them to finance rapid expansion or contraction of their fleets without taking on debt. Only 2% of aircraft were leased in 1980. Now over 40% are... Irish firms manage in excess of 5,000 commercial aircraft, worth over $130bn, accounting for half of all leased planes and a quarter of the fleet globally... The industry in Ireland is now growing so fast, it is skewing the country’s economic data. Official GDP growth of 26% in 2015 was largely the result of lessors buying so many new planes; the rest of the economy probably grew only by about 5%.