They scored highly on measures of ease of doing business, as well as measures of corruption/transparency. They also have flexible labour markets. They both have an established track record for transparency in regulatory institutions, sound management of the public accounts, and a forward-looking monetary policy are well-regarded internationally. Finally, their banking system remained sound and well-capitalised.
The large Australian banking groups, of which the major New Zealand banks are a part of, are now among the largest and highest-credit-quality banks in the world. Australian parents of the big 4 NZ banks are some of the best-rated in the world (4 of the remaining 13 AAs and in the top 20 biggest).