Death and taxes

According to the Organization for Co-operation and Economic Development, only three places—Andorra, Liechtenstein, and Monaco—remain on its list of "uncooperative tax havens" now that the Marshall Islands and Liberia have made certain reforms. (This doesn't mean that the Marshall Islands and Liberia are not tax havens anymore; it just means they aren't evil tax havens.)

One interesting thing about Andorra, Liechtenstein, and Monaco is that all three countries boast extraordinarily high life expectancy rates. Indeed, Andorra's, at nearly 84 years at birth, is the highest in the world. San Marino, Hong Kong, Guernsey, Gibraltar, and the Cayman Islands are also in the top 20, with Jersey not far behind at #22.

Granted, correlation does not, ipso facto, imply causation—Sweden, Japan, and Norway, also in the top 20, are hardly libertarian paradises, and Liberia and the Marshall Islands aren't exactly great places to raise your child—but it's a curious coincidence nonetheless.

UPDATE: Some informed comments here from British tax researcher Richard Murphy.