The purpose of the site is explained this way:
The purpose of this site is to make freely and easily available to the public Richard Posner's largest and greatest body of work — his judicial opinions. The database contains opinions from 1981 to 2006. It will not contain the most recent opinions.
Why this site? While Posner's books and popular writings are easily available to the public, his opinions are difficult or expensive for the public to access, let alone search. This site, for the first time, collects almost all of his opinions in a single searchable and easily readable database.
For lawyers and those interested in law, Posner's opinions have a particular substantive value. One thing that distinguishes the opinions is the effort to try and get at why a given law actually exists, and an effort to try and make sense of the law. That can make them more useful than most case reports.
In addition, the opinions often develop the American general and state common law. Posner is among the judges who feels free to take the rule of Erie as more suggestion than injunction.
Finally, some of the opinions are funny.
I did a number of searches. The first, not surprisingly, was "copyright." Sixty hits came back, the most recent being Assessment Technolgies (2004), the earliest being Rogers Co. Inc. v. Keene Mfg. Co. (1985). I then searched for the world's most popular search term, "sex," and came back with 124 hits, a clear indication that Judge Posner thinks about sex more than twice as often as he thinks about copyright. (See also his 1991 book Sex and Reason). Since Judge Posner is well known for law and economics issues it should not be surprising that he thinks about such issues alot; a real lot: a search of "actual damages" came back with 520 hits, almost 4 times as much as sex, a clear indication that he thinks about economics issues well over 4 times as much as sex.
Judge Posner should also be known for his ruminations and literature (See his revised 1998 book Law and Literature). A search of Kafka reveals 7 references including this one in Glenn v. Secretary of Health & Human Services, a 1987 opinion in which the issue was whether a 46 year old baker's helper was entitled to social security benefits due to an inability to stand up for long periods of time (due to degenerative arthiritis of the hips) and his unsuitability for desk jobs due to his alleged illiteracy. The district court affirmed the SSA ALJ's denial of benefits, a decision the court of appeals affirmed under what appears to be something like an abuse of discretion standard. In tackling the issue of whether Glenn was illiterate within the meaning of the SSA's regulations, Judge Posner wrote:
To decide whether Glenn is "literate" (= marginally educated) or "illiterate" is to impose a dichotomous classification on a continuous phenomenon; but law does that all the time for the sake of administrative simplicity, a pertinent illustration being Stephens v. Heckler, 766 F.2d 284, 286 (7th Cir. 1985). The regulations provide some guidance in performing this unavoidably arbitrary task of classification. They make clear that to be deemed literate you need only be able to read and write well enough to be able to hold simple, unskilled jobs. This is not everyone's idea of literacy; it would not satisfy the distinguished literary critic who said that "He who has read Kafka's Metamorphosis [the story about a man who wakes up one morning to find that he's a giant bug] and can look into his mirror unflinching may technically be able to read print, but is illiterate in the only sense that matters." George Steiner, Literacy, in Steiner, Language and Silence: Essays on Language, Literature, and the Inhuman 3, 11 (1974).
Hamlet is cited 13 times in the database, Bleak House once and Merchant of Venice once, clearly indicating that Judge Posner thinks about Hamlet almost twice as much as Kafka, which may or may not be healthy. One can of course create your own stats and form your own profile, something Professor Wu encourages. Happy searching.