Segregation Indices Compared
"H" Entropy (or Diversity) Index
|
|
K |
|
|
|
H= |
-Σ |
Pk |
Log Pk |
|
|
k=1 |
|
|
Where:
N=total population size
Nk =number of persons in Kth group
Pk = Nk /N
Isolation and Interaction Index
Isolation:
|
|
n |
|
|
x P*x= |
Σ |
[xi/X][xi/ti] |
|
|
i=1 |
|
Interaction:
|
|
n |
|
|
x P*y= |
Σ |
[xi/X][yi/ti] |
|
|
i=1 |
|
Where:
xi = number of X members in the areal subunit i
yi = number of Y members in the areal subunit i
ti = Total population of number of the areal subunit i
X =Number of X members county-wide
Index of Dissimilarity
|
|
n |
|
|
D= |
Σ |
[ti / |pI-P|/2TP(1-P)] |
|
|
i=1 |
|
Where:
ti = Total population of areal subunit i
pi = "minority" population of areal subunit i
T = Total population of whole county
P = "minority" population of whole county, which is subdivided into n areal units.
Adapted from: Segregated Diversity: Race-Ethnicity, Space, and Political Fragmentation in Los Angeles County, 1940-1994 by Philip J. Ethington Department of History ,University of Southern California