Harper's Index is a monthly feature in Harper's Magazine, and has run since 1984. The Index consists of a number of statistics arranged in an order, some of them related to each other, some of them standing on their own, some of them on serious matters, and some of them for novelty effect. Some of the statistics relate to articles elsewhere in the magazine.
The Index is usually the first, and sometimes the only part of Harper's, that I read. This is not so much because of its quality, as that it is very breezy, since it features information in a convenient one-line format. It is a series of written sound bites.
Given my overall liberal politics (which is Harper's editorial bias), I find the lack of context and critical viewpoint in Harper's Index annoying. If I was more conservative, I would probably find them infuriating. The use of statistics allows the editor of the Index to snidely and coyly make typical liberal talking points, without giving any type of context that would explain them or allow for nuance. If there are such a thing as gotcha questions, these are gotcha answers. So while I would recommend reading the Index if you are ever in a waiting room with a copy of Harper's, please don't believe anything you read.