> The largest-ever study of alleged racial profiling during traffic stops has found that blacks, who are pulled over more frequently than whites by day, are much less likely to be stopped after sunset, when "a veil of darkness" masks their race.
> The Stanford team decided to repeat the analysis using the much larger dataset that they had gathered. First, they narrowed the range of variables they had to analyze by choosing a specific time of day -- around 7 p.m. -- when the probable causes for a stop were more or less constant. Next, they took advantage of the fact that, in the months before and after daylight saving time each year, the sky gets a little darker or lighter, day by day. Because they had such a massive database, the researchers were able to find 113,000 traffic stops, from all of the locations in their database, that occurred on those days, before or after clocks sprang forward or fell back, when the sky was growing darker or lighter at around 7 p.m. local time.
> The largest-ever study of alleged racial profiling during traffic stops has found that blacks, who are pulled over more frequently than whites by day, are much less likely to be stopped after sunset, when "a veil of darkness" masks their race.
> The Stanford team decided to repeat the analysis using the much larger dataset that they had gathered. First, they narrowed the range of variables they had to analyze by choosing a specific time of day -- around 7 p.m. -- when the probable causes for a stop were more or less constant. Next, they took advantage of the fact that, in the months before and after daylight saving time each year, the sky gets a little darker or lighter, day by day. Because they had such a massive database, the researchers were able to find 113,000 traffic stops, from all of the locations in their database, that occurred on those days, before or after clocks sprang forward or fell back, when the sky was growing darker or lighter at around 7 p.m. local time.