Thursday, October 29, 2015

Police Stops in Berkeley California and Ferguson Missouri- Guest Post by Valerie Trahan

Valerie Trahan
2045 Emerson (Lower)
Berkeley, CA

Attorney General Kamala Harris
Attorney General's Office
California Department of Justice
Attn: Public Inquiry Unit
P.O. Box 944255
Sacramento, CA 94244-2550


Title: Is Berkeley more racially biased than Ferguson Missouri?

There has been much media coverage about the racial biases and negative police practices associated with Ferguson Missouri. In light of the recent articles about Police Stops in Berkeley, CA, I took it upon myself to see if the disparities were in fact as biased as advertised. I was also curious to see if in fact police stops in Berkeley, CA were more prevalent than in the much publicized practices in Ferguson Missouri.

For my inquiry I used the legally recognized One Proportion Z Test Statistics Calculator. The calculation measures expected results based on population with observed results. The calculator also converts the query in to standard deviations to measure for disparate treatment results or (happenings no attributed to chance).

I started with the East Bay Express Article (regarding Berkeley,CA) on police stops to gather my data. To make sure my query was honest I subtracted 557 police stops from the total to get my total of 4658 stops. Keep in mind the African American Population of Berkeley is 8% .I also want people to keep in mind that Berkeley is a University Town and does get traffic from other visitors from other cites. Berkeley has Oakland to the south and San Francisco across the bay. However, my statistical findings were astonishing. Based on the African American population of Berkeley the expected number of stops for African Americans was roughly 373. (372.64 rounded up). However the observed proportion of 30.5% or 1421 detained African Americans is probative evidence of bias.  The Z-Test showed 56 standard deviations! (anything over 5 is considered intentional discrimination;( I also used the legally recognized binomial probability method (heads or tails test) and computed an equally astonishing 0.000001 % probability of a random event. In other words the data suggests that Police are targeting African Americans while in Berkeley.

We move onto Ferguson Missouri. Ferguson Missouri is 67% African American. According to the article in The Atlantic blacks in Ferguson amounted to 86% of all police stops. Again the expected number based on the sample size of 5384 was 3607 stops. However, observed stops for African Americans constituted 4630. This is 1023 more stops than expected. The Z-Test Standard Deviation number computed to 29.649 standard deviations. The Binomial(heads or tails test) also came to 0.000001. The Ferguson numbers while horrific dont compare to the disparity in Berkeley, California. I have lived in Berkeley all my life and have recently retired from teaching at Berkeley High School. The empirical question must be asked: Is Berkeley, California more racist than Ferguson, Missouri?
Valerie Trahan
Masters Degree in Education; Harvard University
phone: 510-689-6123
DATA and ARTICLES are attached.