I tried several histograms, scatters, bar charts, box plots to catch a visually significant meaning in the data. However, only looking at the count of the stops per race, gender, age does not imply any. Then, I decided to deep dive into the below columns:
I calculated 2 scores:
- DIS: Driver Impact Score
- PRS: Police Response Score
I read several articles* about crimes, punishments and police rights/authorizations in both states to come up with a weighted score of what the driver did and how the driver responded. Then, I worked on this scores per race, age and gender.
I plotter a scatter diagram of Driver Impact Score vs Police Response Score for both countries. Then, I tried to fit them to simple lineer regression. Even though I observe some differences in fitted line parameters, it did not signify a visual insight due to the imbalanced data in terms of race and scores as can seen below:
Los Angeles, CA
Columbus, OH
Hence, I decided to dig into the correlation, AND BINGO! I guess I found some correlations between police behavior & race in Columbus!
Here is the evidences:
Clue1:
On the contrary of Los Angeles's racial correlation matrix, I see that there is a positive correlation between Hispanics & driver impact score. However, I am much more interested in the negative correlation between blacks & police response score AND positive correlation between whites & police response score.
Clue2:
When we check the box-plot of Police Response Score per race, the black race is distinguished from the other races as can seen below.
My aim would be to make further analysis if this distinguishment is significant or not.
Side project on d3
While analysing the histogram of the data, I noticed that there is a significant decreasing trend in stop count in Los Angeles. During the same period, Police Budget decreased, too. I noticed that Los Angeles stop count trend is highly consistent with the US Police Service budget trend, while it is not the case for Columbus as below.
Los Angeles City is one of the biggest contributor of the Police spending. Hence, it is directly effected by the country budget. There is no statistical testing for this, it is obvious. So, as the side project on d3, I will show stop counts & estimated budgets on a timely basis.
