As I suspected (and hoped) crime was not up last year. Of course it was up some places (and thus down in others). What a country we live in: we can send a man to the moon and don’t know how many people were murdered in 2014 until late September, 2015. When the 2015 figures come out in a year…
Tag: stats
NYPD Discipline
Some stats about the NYPD in the New York Times. Bratton is giving more discretion to local commanders for disciplining cops for minor offenses. That’s good. It’s another move away from the micro-managed overly top-down approach of former Commissioner Ray Kelly. The article then tries to say Bratton is not applying Broken Windows within his own department… but that once…
Value Over Replacement Cop
This was gonna be my idea! “Bobbies and Baseball Players: Evaluating Patrol Officer Productivity Using Sabermetrics.” So kudos to Luke Bonkiewicz because he actually researched and wrote the article and I didn’t. Here’s the abstract from the current issue of Police Quarterly (2015, Vol. 18(1) 55–78): Police officer productivity is an understudied topic in police research. Prior studies on productivity…
From the [not so] sharp minds at ProPublica
I’ve written before about their foolish and inaccurate claim that the black-to-white racial disparity among those shot by police is 21 to 1. I said, given the group they look at, the number is 9 to 1. But without any slight-of-hand or misleading highlighting of statistical outliers, the actually black-to-white racial disparity, the take-home stat, is 4 to 1. More…
Confidence Intervals
* This is a footnote to the above post. (and the third in a series on basic math concepts) The ProPublica people don’t explain confidence intervals at all in this piece, but in their original they say, “a 95 percent confidence interval indicates that black teenagers are at between 10 and 40 times greater risk of being killed by a…
What’s your C.O.P. score?
You know, “Crimes prevented Over rePlacement.” (Or maybe just “C-POR.”) Like WAR, wins above replacement, but for cops. The idea is to break crime down by beat/post and looking at it over time (a long time, like years). Wouldn’t it be nice to know if there actually was less crime on your post while you were policing. Of course would…
Racial disparity in police-involved homicides: 4:1
Trying to set the record straight is a bit like pissing into the wind. The substantively wrong pro-publica story has now been repeated by every news source I can find. I suspect that over time the idea that from 2010-2012, blacks males 15-19 years-old were 21 times more likely than non-hispanic-whites males to be killed by police will simply become…
Black are 4 times more likely than whites to be killed by police
[Update: Cut to the chase. You might just want to read my summary post.] Related to the “not 21 times” previous post, I received a tweet from one of the authors: “Differences in our methodologies: you count Hispanic homicides as white… deflate the results.” So back to running stats for me. But there’s a problem in that the UCR homicide…
Black teens are not 21 times more likely than whites to be shot and killed by police
[Update: Cut to the chase. You might just want to read my summary post.] One of my liberal de Blasio-loving not-so-fond-of-cops friend send me an email with the subject “you gotta check yo facts” and a link to ProPublica: “Young black males in recent years were at a far greater risk of being shot dead by police than their white…
Rates help us compare
This is the second of two postson basic math. Use rates when you want compare something in groups of different sizes. Say New York City has 400 homicides a year. Say Baltimore City has 300 homicides. Is New York more dangerous than Baltimore because New York has more homicides. No. Because New York is much larger. But the homicide numbers…