It takes less time for a badly addressed letter to get back to the US from New Zealand than it does to get back there from Canada. At least that's what Chong, La Porta, Lopez-de-Silanes and Shleifer find in a test of public sector efficiency [working paper version]
Here's a snip from Table 2, showing the proportion of test letters making it back to sender, the proportion doing so within 90 days, and the average number of days to get the letter back.
I note that New Zealand's postal service faces private sector competition, unlike some other countries' postal services.
NZ Post advertises that its cheapest international option takes 6-10 working days to ship to the US. The USPS gives no delivery estimates on its first class international mail offerings, but its Priority Mail option, more expensive, is 6-10 working days.
I'd expect that the letter to New Zealand spent a long time on a slow boat getting here.
More broadly, they find that measures of bureaucratic quality, red tape, education, ease of doing business, contract enforcement, infrastructure quality, and political accountability all affect mail efficiency in the expected directions.
HT: Bryce Wilkinson