The surveys themselves have a built-in bias. As many deans acknowledge, the results are skewed because graduates with high-paying jobs are more likely to respond than people earning $9 an hour at Radio Shack. (Those who don’t respond are basically invisible, aside from reducing the overall response rate of the survey.)

Certain definitions in the surveys seem open to abuse. A person is employed after nine months, for instance, if he or she is working on Feb. 15. This is the most competitive category — it counts for about one-seventh of the U.S. News ranking — and in the upper echelons, it’s not unusual to see claims of 99 percent and, in a handful of cases, 100 percent employment rates at nine months.

A number of law schools hire their own graduates, some in hourly temp jobs that, as it turns out, coincide with the magical date. Last year, for instance, Georgetown Law sent an e-mail to alums who were “still seeking employment.” It announced three newly created jobs in admissions, paying $20 an hour. The jobs just happened to start on Feb. 1 and lasted six weeks.

A spokeswoman for the school said that none of these grads were counted as “employed” as a result of these hourly jobs. In a lengthy exchange of e-mails and calls, several different explanations were offered, the oddest of which came from Gihan Fernando, the assistant dean of career services. He said in an interview that Georgetown Law had “lost track” of two of the three alums, even though they were working at the very institution that was looking for them.

As absurd as the rankings might sound, deans ignore them at their peril, and those who guide their schools higher up the U.S. News chart are rewarded with greater alumni donations, better students and jobs at higher-profile schools.

“When I was a candidate for this job,” said Phillip J. Closius, the dean of the University of Baltimore School of Law, “I said ‘I can talk for 10 minutes about the fallacies of the U.S. News rankings,’ but nobody wants to hear about fallacies. There are millions of dollars riding on students’ decisions about where to go to law school, and that creates real institutional pressures.”

Mr. Closius came from the University of Toledo College of Law, where he lifted the school to No. 83 from No. 140, he said. Among his strategies: shifting about 40 students with lower LSAT scores into the part-time program. Because part-time students didn’t then count in the U.S. News survey — the rules have since been changed — Toledo’s bar passage rate rose, which helped its ranking.