How to turn statistics into damned lies

From the NY Times:

The missing statistics used to appear in a supplement to the Mayor’s Management Report that in recent years has been published exclusively online. Some of the supplementary indicators have been eliminated entirely. In other cases, groups of indicators were combined to provide broad strokes of information, but not the detail that was available previously.

For example, more than 80 supplementary indicators for the Police Department have been condensed or dropped. The report, for example, no longer discloses how quickly the police responded to crimes in progress.

Twenty-eight separate categories of school crimes — offenses ranging from disorderly conduct to murder — have been boiled down to three broad ones — “major crimes,” “other criminal categories” and “other incidents.”

And gone is the number of hours between arrest and arraignment, a measurement that reveals how much time police officers spend in court rather than on patrol and whether suspects are held for longer than 24 hours without being charged with a crime.

“What are the advocates in the field concerned about, and how does this change or diminish their ability to assess that?” asked Arthur Eisenberg, legal director of the New York Civil Liberties Union. “Advocates sought to strengthen the 24-hour rule. It’s a major point of contention. That information used to be publicly available. Now it is not available. School safety: Advocates believe the police should not enforce minor offenses in schools. That information used to be available. Now it is no longer there.”

Photo from the NY Sun