An Excel-lent exercise

Zane Sparling, formerly with the Merc, is getting a workout right away at his new gig, with the O. Here he gets into the statistics on race and traffic stops by the Oregon state police. Surprise! People of color get pulled over, and ticketed, more often than white people.

They have a hard time proving it to me. The sample size around here is way too small. When was the last time you saw a cop on a freeway in, or anywhere near, Portland? Haven't seen a state trooper around town, except for the riots, in many moons. And there is no meaningful traffic enforcement by the local police (unofficially on strike for months now) on the city streets, either.

Meanwhile, the numbers look better for the Multnomah County sheriff, and so down toward the bottom of the story, old Mike Reese is taking a bow for how progressive his shop is. He'd be singing a different tune if the numbers came out differently. Live by the statistics, die by the statistics.

Leafing through the report that's covered in Sparling's story, I'm not sure I'd put a whole lot of stock in what the researchers found, or didn't find. They start with something called the "Veil of Darkness analysis," and already it sounds goofy. 

Based on the assumption that it is easier for an officer to discern race/ethnicity during the day when it is light versus the night when it is dark, this analysis compares stop rates for minority individuals to those for white individuals during the time windows surrounding sunrise and sunset. If, as demonstrated by the statistics that result from the Veil of Darkness test, minority individuals are more likely to be stopped in the daylight when race/ethnicity is easier to detect, then there is evidence of a disparity.


They also get into whether police searches are racially biased, looking primarily at how many unsuccessful searches are conducted in different racial categories. At least, I think that's what this means:

The Hit-Rate test compares relative rates of successful searches (i.e., those resulting in the seizure of contraband) across racial/ethnic groups. It is based on the assumption that if search decisions by officers are based on race/ethnicity neutral criteria, then success rates should be similar, if not identical, across different racial/ethnic categories. If, however, search success rates differ and the search success rates for minority individuals are significantly lower than those reported for white individuals, then there is evidence of a disparity.


These statistics exercises are interesting enough, but you wonder whether they're ever going to make a difference in police behavior – and whether they should. Whatever. The Legislature commands that we do them. Bring on the PERS! But remember what Mark Twain said.