The Probability of A, given B

A Statistical look at Black versus White Crime
2011 FBI Statistics

FBI Statistics (2011)

SOURCE:  http://www.fbi.gov/about-us/cjis/ucr/crime-in-the-u.s/2011/crime-in-the-u.s.-2011/tables/expanded-homicide-data-table-6

RAW DATA

Race of victim      Total Race of offender Sex of offender
White Black Other Unknown Male Female Unknown
White  3,172 2,630 448 33 61 2,810 301 61
Black  2,695 193 2,447 9 46 2,385 264 46
Other race  180 45 36 99 0 155 25 0
Unknown race 84 36 27 3 18 63 3 18
Total by race 6,131 2,904 2,958 144 125 5,413 593 125
Sex of victim      Total Race of offender Sex of offender
White Black Other Unknown Male Female Unknown
Male  4,304 1,834 2,289 87 94 3,760 450 94
Female  1,743 1,034 642 54 13 1,590 140 13
Unknown sex 84 236 27 3 18 63 3 18
Total by sex 6,131 2,904 2,958 144 125 5,413 593 125

The data above is what is presented in the FBI statistics for 2012.  I have added total lines for race and sex in blue font. 

 In this analysis, we are only interested in Race data, which is highlighted in orange, and of that only Black on White (and White on Black) statistics, which is highlighted in magenta (pink).
 

Analysis

Frequency of Occurrence (percentage)

2011

offender

Ratio (B/W)
victim White Black 2.0
White 83% 14%
Black 7% 91%
      1.1

Frequency of Occurrence (percentage)

What the above table says in words is as follows:

83% of  White victims offenders were White, and 14% were Black

 7% of Black victims offenders were White, and 91% were Black

(Black-on-White) divided by  (White on White) equals 1.9     
                   14%       /            7%                      =        2.0 
Blacks murder Whites at approximately twice the frequency that Whites murder Blacks

(Black-on-Black) divided by  (White on White) equals 1.1     
                  91%        /            84%                    =        1.1    
Frequency of Black-on-Black murder is 10% greater than White-on-White

The Frequency of Occurrence Analysis, above, does not factor in the great difference in population -- specifically, the Black population is only 12.5 % of the total population.  Or in other words, there are 8 Whites for every 1 Black

Murder Rate (Occurrence/100,000) by Race

Population estimate

88% 12%  
Total  White Black  
238,952,977 210,278,620 28,674,357  
offender B/W
victim White Black 17.0
White 1.25 1.56  
Black 0.09 8.53  
      6.8

Murder Rate (Occurrence/100,000) by Race

In the table above, population is factored in buy dividing the frequency of occurrence by the sub-population.  The total population estimate is given in the FBI data in other tables.  The formula for calculation the Murder rates is:

Murder Rate equal frequency-of-occurrence divided by sub-population

What the above table says in words is as follows:

The White-on-White murder rate (per 100,000 of the White population) is 1.25
The Black-on-Black murder rate (per 100,000 of the Black population) is 8.53
The Black-on-Black murder rate is 6.8 times the White-on-White murder rate.

The Black-on-White murder rate (per 100,000 of the respective sub-population) is 1.56
The White-on-Black murder rate (per 100,000 of the respective sub-population) is 0.09
The Black-on-White murder rate is 17.0 times the White-on-Black murder rate.

©2013 Simon Revere Mouer III, all rights reserved