Racial Disparity Ratio
The racial disparity ratio calculates the relationship between two numbers indicating how many times the first number contains the second. For example, if a bowl of fruit contains eight oranges and six lemons, then the ratio of oranges to lemons is eight to six. In the case of racial disparity ration, the exclusion rate for the highest group is divided by the average exclusion rate for the other racial groups.
Steps 
Example District Name 
Akron City 
1 
Identify the highest exclusion rate by a racial group in the district. 
77.0 
2 
Identify the racial group with the highest exclusion rate. 
Black 
3 
Calculate the number of different racial groups in the district. 
7 
4 
Calculate Average Exclusion Rate of the other Racial Groups in the district. 
19.5 
5 
Calculate the Racial Disparity Ratio by dividing the Highest Exclusion rate (Step 2) by the Average Exclusion Rate (Step 4) 
4.0 
1 
Identify the highest exclusion rate. Calculate an exclusion rate for each racial group present in a particular school. Ohio divides its student population into seven racial groups: American Indian, Asian, Black, Hispanic, Multiracial, Pacific Islander, and white. The Exclusion rate is the total of the following disciplinary occurrences: expulsions, outofschool suspensions, Removal by Hearing officer and Emergency Removal by District Personnel divided by total enrollment for the school. For some school districts, this is an approximation since these schools/districts report enrollment as "less than10" and exclusions as "less than 10". In those circumstances, we used "5" as the enrollment number and "3" as the exclusion number. Please check with your school district for more accurate information) For the example below, Akron City, the highest exclusion rate was 77 per 100 students. That is in Akron 77 exclusions occurred per 100 Black students. Focusing on the highest exclusion rate, the mean or average rate was 51.1. That is, on average, 51.1 exclusions occurred per Black 100 students. For half the districts, the highest exclusion rate was 33.8. That is, half the schools were excluding one racial group at 33 exclusions per 100 students from the particular racial group. Three schools had no exclusions. The maximum highest exclusion rate was 420, that is 420 exclusions per 100 students from the specific racial group.
Highest Exclusion Rate by Organization Type Community (charter) school had the highest mean exclusion rate by racial grouping at 75.3 exclusions per 100 students in a particular racial group. While Public District mean was 40.3. Community schools had a higher median with half their schools having exclusion rates over 60 per 100 students. While some Public Districts reported no exclusions, every reporting community (Charter) school had some exclusions. This difference between community (Charter) schools and Public District was statistically significant (p<.000); that is a zero probability that this difference occurred by chance alone
Highest Exclusion Rate * Typology of Public Districts Type 7 Urban schools had the highest mean exclusion rate by racial grouping at 65.4 exclusions per 100 students in a particular racial group. While Type 3 Suburban schools had the lowest mean, 17.9. Type 8 Urban schools had the highest median with half their schools having exclusion rates over 55.8 per 100 students. Only Type 2 Rural districts reported districts with no exclusions and type 8 urban districts had the highest minimum (36.10) While type 7 Urban schools had the highest rate (300 exclusions per 100 students). This difference between Public Districts based on typology was statistically significant (p<.000); that is a zero probability that this difference occurred by chance alone.


2 
Identify the group with the highest exclusion rate. Ohio divides its student population into seven racial groups: American Indian, Asian, Black, Hispanic, Multiracial, Pacific Islander, and white. For each district, we identified the racial group with the highest exclusion rate. Every racial group was represented. But the representation wasn't equitable. For instance: for 354 of the districts (40.3%) blacks had the highest exclusion rate; for 119 of the districts(13.5%) whites had the highest exclusion rate; Asians with had the highest exclusion rate in 26 (3.0%) of the schools/districts ; while, American Indians, with a mean of 92.9 exclusions per 100 students, had the highest mean exclusion rate in 63 of the districts. The mean highest exclusion rate was lowest for whites (29.4) This difference base on race was statistically significant. (p=.000) That is zero probability that differences occurred by chance alone.


3 
Calculate the number of different racial groups in a school/district. Ohio reports racial data in seven categories: American Indian or Alaskan Native, Asian, Black or African American (nonHispanic), Hispanic, Multiracial, Pacific Islander, and White (nonHispanic). It is important to remember that the 879 districts include both multiple school districts and a single school district. However, no district had only one racial group. The smallest number of racial groups in a school/district was 2; 6 of the districts (.7%) had only two racial groups. Two hundred sixtysix districts (30.3%) had all seven racial groups. Schools with more racial groups had overall lower mean highest exclusion rate. This difference based on racial groups in a school/district was statistically significant. (p=.002) That is, there is less than a .2% probability that differences occurred by chance alone.


4 
Calculate Average Exclusion Rate of all Racial Groups in the district EXCEPT the group with the highest Exclusion Rate. In calculating our ratio, we compared the racial group with the highest exclusion rate to the rest of the students in that particular school/district. The mean average rate of other racial groups 10.9; the median average exclusion rate was 4.2; that is half the schools had average exclusion rate of fewer than 4.2 exclusions per 100 students. Several schools had no exclusions for other groups. The maximum average exclusion rate for other schools was 147.6.


5 
Calculate the Racial Disparity Ratio. The racial disparity ratio was calculated by dividing the Highest Exclusion rate (Step 2) by the Average Exclusion Rate (Step 4). We can calculate the ratio for 879 districts. The ratio compares values. A ratio says how much of one thing there is compared to another thing. Ratio 3:1. There are three blue squares to 1 yellow square. We report the ratio as a single number because in all cases, the second number is one. That is, a racial disparity ratio of 2.3 means that in a particular school district, the group with the highest exclusion rate has 2.3 times more than the average racial exclusion rate for the other group. In this case, the average racial disparity ratio is 15.6 which means that for Ohio schools, the group with the highest racial exclusion rate is 15.6 times more likely to be excluded than the other students at the particular district. Half the districts had a racial disparity ratio above 4.9
Community (Charter) Schools had a lower mean racial disparity ratio than Public districts. They also had a lower median with half their schools having a racial disparity ratio of less than 3.6. That is, in half the community charter schools, the racial group with the highest exclusions were only 3.6 times more likely to be excluded compared to the 5.4 times more likely in Public Districts. This difference in a racial disparity ratio based on Organization type was statistically significant (p=.005). That is there is less than a .5% chance that this difference in racial disparity ratio based on organization type occurred by chance alone
Type 8 Urban districts had the lowest mean racial disparity ratio. They also had the lowest median with half their schools having a racial disparity ratio of less than 3.0. That is, in half the Type 8 Urban Public districts the racial group with the highest exclusions were only 3.0 times more likely to be excluded compared to the 8.7 times more likely in Type 3 Small Town schools/districts. This difference in a racial disparity ratio based on Typology of Public District was statistically significant (p=.000). That is there is zero chance that this difference in racial disparity ratio based on occurred by chance alone.
