Overview

The following tables summarize the characteristics of tract categories in the MixedMetro tract classification scheme described in detail in Holloway, Wright and Ellis (2011).1 Briefly, the scheme uses population shares in six racial categories - White, Black, Latino, Asian, Native American, and Other - to classify tracts by their racial diversity (measured with scaled entropy: min=0, max=1) as follows:

Low diversity tracts: scaled entropy ≤0.3707 or largest group > 80% of tract population

High diversity tracts: scaled entropy ≥0.7414 and largest group ≤ 45% of tract population

Moderate diversity tracts: those not in the low and high diversity categories

Low and moderate diversity tracts (not high diversity) are further identified by the group with the largest share of the tract population, producing 13 potential categories: six low diversity categories identified by the largest group present (e.g. low diversity White, low diversity Black, etc); six moderate diversity categories identified by the largest group present (e.g. moderate diversity White, moderate diversity Black, etc); and one high diversity category with no largest group identified.

The summary statistics presented below describe the characteristics of these categories using the set of all tracts in the US from the 1990, 2000 and 2010 censuses normalized to 2000 tract boundaries. They exclude tracts with fewer than 50 people in them in any of these three censuses.

Category abbreviations in all tables

LDW = Low Diversity White, LDB = Low Diversity Black, LDL = Low Diversity Latino, LDA = Low Diversity Asian, LDNA = Low Diversity Native American, MDW = Moderate Diversity White, MDB = Moderate Diversity Black, MDL = Moderate Diversity Latino, MDA = Moderate Diversity Asian, MDNA = Moderate Diversity Native American, MDO = Moderate Diversity Other, HD = High Diversity

Mean entropy and group share by MixedMetro category, pooled for 1990, 2000, 2010

This table reports the means of entropy and group shares by tract type. Mean entropy in low diversity White (LDW) and low diversity Black (LDB) tracts is lower than in other low diversity tract types. The majority share in LDW and LDB tracts averages over 90%. For low diversity Latino (LDL) and low diversity Asian (LDA) tracts, the majority share is in the mid 80% range.

Among moderate diversity tracts, moderate diversity White (MDW) and moderate diversity Black (MDB) tracts have the lowest entropy scores and the highest majority group shares. After Whites, Blacks and Latinos have the largest, approximately equal, mean population shares in moderate diversity White tracts. Whites have the second largest mean population share in all non White moderately diverse tracts. In moderately diverse Latino (MDL) tracts, Whites and Blacks are the second and third largest groups on average. In moderately diverse Asian (MDA) tracts, Whites and Latinos occupy second and third positions.

High diversity (HD) tracts have shares of Whites, Blacks, Latinos and Asians that average between 20% to 30%.

Category Entropy White Black Latino Asian NatAm Other
LDW 0.19003 0.91757 0.02793 0.02916 0.01611 0.00782 0.00149
LDB 0.19472 0.05639 0.90523 0.02756 0.00495 0.00371 0.00230
LDL 0.23741 0.07658 0.02406 0.88056 0.01359 0.00308 0.00221
LDA 0.30701 0.08034 0.00932 0.05297 0.84968 0.00381 0.00395
LDNA 0.20106 0.07178 0.00244 0.02676 0.00186 0.89649 0.00075
MDW 0.51757 0.64401 0.13578 0.13941 0.06144 0.01477 0.00470
MDB 0.51342 0.25935 0.59176 0.11284 0.02433 0.00702 0.00484
MDL 0.55228 0.23196 0.11211 0.58080 0.06103 0.00853 0.00567
MDA 0.58608 0.23031 0.04444 0.15828 0.55521 0.00525 0.00659
MDNA 0.48557 0.29887 0.02214 0.06774 0.00924 0.59960 0.00247
MDO 0.69882 0.35545 0.09257 0.16436 0.00000 0.00000 0.38762
HD 0.77837 0.29513 0.21610 0.25558 0.19728 0.01460 0.02143

Standard deviation of entropy and group share by MixedMetro category, pooled for 1990, 2000, 2010

There is fairly tight clustering around the means in most categories. Moderately diverse tracts have greater standard deviations than low diversity tracts.

Category Entropy White Black Latino Asian NatAm Other
LDW 0.10585 0.05950 0.04167 0.03282 0.02079 0.01519 0.00279
LDB 0.10591 0.06633 0.07205 0.04001 0.00890 0.00381 0.00378
LDL 0.09744 0.05917 0.04178 0.06525 0.02378 0.00566 0.00278
LDA 0.06618 0.04862 0.00940 0.03405 0.04510 0.00299 0.00413
LDNA 0.09562 0.07202 0.00602 0.03407 0.00267 0.07215 0.00140
MDW 0.09164 0.10591 0.12342 0.11038 0.07270 0.03705 0.00836
MDB 0.09491 0.13570 0.10407 0.11854 0.03848 0.01469 0.01031
MDL 0.09692 0.12700 0.11208 0.10950 0.07741 0.01860 0.00806
MDA 0.09354 0.10976 0.05765 0.10496 0.11673 0.00517 0.00793
MDNA 0.09010 0.11111 0.06077 0.08753 0.02174 0.10721 0.01012
MDO NA NA NA NA NA NA NA
HD 0.03077 0.09736 0.09211 0.09089 0.09716 0.02944 0.03777

Mean of entropy and group share by MixedMetro category by year

The clearest trend here is the rise in mean entropy in almost all tract categories from 1990-2010. High diversity tract mean entropy is stable across the decades.

The rise in within class entropy by year does not correspond to a decline in largest group share. This implies that a growing presence of multiple groups must be the major force driving up entropy, or diversity scores, from 1990-2010.

Category Year Entropy White Black Latino Asian NatAm Other
LDW 1990 0.15943 0.92717 0.02900 0.02489 0.01284 0.00562 0.00047
LDW 2000 0.20053 0.91601 0.02667 0.02859 0.01710 0.00908 0.00272
LDW 2010 0.22477 0.90451 0.02782 0.03655 0.01999 0.00969 0.00153
LDB 1990 0.17430 0.06840 0.90406 0.02175 0.00306 0.00188 0.00085
LDB 2000 0.19606 0.05027 0.91002 0.02663 0.00537 0.00418 0.00380
LDB 2010 0.21552 0.04983 0.90142 0.03486 0.00656 0.00520 0.00228
LDL 1990 0.23350 0.09349 0.02135 0.87027 0.01090 0.00196 0.00204
LDL 2000 0.24158 0.07588 0.02339 0.88120 0.01302 0.00375 0.00292
LDL 2010 0.23648 0.06645 0.02633 0.88656 0.01575 0.00323 0.00175
LDA 1990 0.29504 0.10474 0.00638 0.04422 0.84220 0.00148 0.00098
LDA 2000 0.31296 0.07335 0.01002 0.04806 0.85563 0.00513 0.00791
LDA 2010 0.30982 0.07033 0.01065 0.06275 0.84955 0.00421 0.00258
LDNA 1990 0.19259 0.08329 0.00171 0.02190 0.00087 0.89193 0.00029
LDNA 2000 0.19984 0.07021 0.00229 0.02406 0.00156 0.90068 0.00154
LDNA 2010 0.21104 0.06169 0.00336 0.03464 0.00318 0.89665 0.00036
MDW 1990 0.49057 0.64433 0.15015 0.13847 0.05399 0.01127 0.00178
MDW 2000 0.52169 0.64684 0.13520 0.13451 0.05979 0.01574 0.00812
MDW 2010 0.52921 0.64157 0.12830 0.14385 0.06687 0.01594 0.00357
MDB 1990 0.48024 0.28531 0.58843 0.09956 0.02003 0.00479 0.00188
MDB 2000 0.51667 0.26009 0.59557 0.10576 0.02380 0.00741 0.00761
MDB 2010 0.53166 0.24222 0.59055 0.12744 0.02752 0.00808 0.00431
MDL 1990 0.52713 0.24626 0.10706 0.57876 0.05788 0.00678 0.00325
MDL 2000 0.55770 0.23161 0.10926 0.58173 0.05913 0.00918 0.00926
MDL 2010 0.55928 0.22601 0.11635 0.58100 0.06377 0.00882 0.00415
MDA 1990 0.57797 0.25975 0.05207 0.14092 0.54089 0.00363 0.00269
MDA 2000 0.59272 0.22611 0.04176 0.15566 0.55899 0.00614 0.01149
MDA 2010 0.58498 0.22031 0.04296 0.16776 0.55885 0.00534 0.00487
MDNA 1990 0.45966 0.31945 0.02244 0.04919 0.00790 0.60018 0.00066
MDNA 2000 0.49538 0.29007 0.02435 0.07124 0.00771 0.60099 0.00597
MDNA 2010 0.49521 0.29202 0.02020 0.07743 0.01134 0.59810 0.00093
MDO 1990 0.69882 0.35545 0.09257 0.16436 0.00000 0.00000 0.38762
HD 1990 0.76788 0.28342 0.22639 0.26529 0.20044 0.01379 0.01067
HD 2000 0.78499 0.30023 0.20635 0.25580 0.19382 0.01458 0.02938
HD 2010 0.77458 0.29292 0.22272 0.25344 0.19972 0.01477 0.01650

Standard deviation of entropy and group share by MixedMetro category by Year

There are no clear trends here. The distributions around the mean appear to be relatively stable by year.

Category Year Entropy White Black Latino Asian NatAm Other
LDW 1990 0.10636 0.06381 0.04995 0.03490 0.01993 0.01568 0.00193
LDW 2000 0.10127 0.05584 0.03680 0.03004 0.02052 0.01508 0.00361
LDW 2010 0.09700 0.05400 0.03201 0.03148 0.02163 0.01408 0.00203
LDB 1990 0.11345 0.08215 0.08528 0.04218 0.00833 0.00396 0.00273
LDB 2000 0.10103 0.05807 0.06548 0.03687 0.00868 0.00318 0.00493
LDB 2010 0.09802 0.05194 0.06205 0.03968 0.00936 0.00344 0.00256
LDL 1990 0.09977 0.07388 0.04728 0.07517 0.02349 0.00600 0.00343
LDL 2000 0.09637 0.05505 0.03963 0.06219 0.02234 0.00538 0.00317
LDL 2010 0.09674 0.04866 0.03962 0.05997 0.02487 0.00557 0.00165
LDA 1990 0.06697 0.05654 0.01020 0.03462 0.04822 0.00275 0.00174
LDA 2000 0.06376 0.03713 0.00949 0.02502 0.03963 0.00235 0.00450
LDA 2010 0.06733 0.04651 0.00841 0.03789 0.04698 0.00278 0.00169
LDNA 1990 0.10264 0.08492 0.00597 0.03311 0.00196 0.08284 0.00098
LDNA 2000 0.09130 0.06419 0.00693 0.02995 0.00191 0.06511 0.00185
LDNA 2010 0.09248 0.06404 0.00483 0.03786 0.00339 0.06776 0.00059
MDW 1990 0.08741 0.10282 0.13766 0.11912 0.07037 0.03593 0.00585
MDW 2000 0.09213 0.10485 0.12322 0.11002 0.07120 0.03776 0.01121
MDW 2010 0.09050 0.10835 0.11421 0.10535 0.07470 0.03698 0.00544
MDB 1990 0.08844 0.14196 0.09264 0.12420 0.04027 0.01690 0.00470
MDB 2000 0.09423 0.13416 0.10323 0.11528 0.03665 0.01355 0.01289
MDB 2010 0.09400 0.13023 0.11133 0.11611 0.03859 0.01397 0.00975
MDL 1990 0.09449 0.13273 0.12035 0.10635 0.08285 0.02125 0.00581
MDL 2000 0.09737 0.12805 0.11232 0.10755 0.07545 0.01795 0.01039
MDL 2010 0.09588 0.12317 0.10799 0.11221 0.07628 0.01776 0.00578
MDA 1990 0.10237 0.10096 0.07164 0.10441 0.12027 0.00461 0.00395
MDA 2000 0.09155 0.10900 0.05518 0.10657 0.11512 0.00584 0.00851
MDA 2010 0.09060 0.11186 0.05195 0.10307 0.11592 0.00473 0.00712
MDNA 1990 0.09222 0.10253 0.06279 0.07732 0.02429 0.10717 0.00215
MDNA 2000 0.08797 0.11526 0.06694 0.08769 0.01593 0.10984 0.01731
MDNA 2010 0.08789 0.11282 0.05467 0.09277 0.02386 0.10640 0.00085
MDO 1990 NA NA NA NA NA NA NA
HD 1990 0.02269 0.08345 0.08713 0.09279 0.08685 0.03434 0.03567
HD 2000 0.03484 0.09822 0.09621 0.09220 0.09914 0.02969 0.03945
HD 2010 0.02687 0.09896 0.08858 0.08929 0.09733 0.02816 0.03522

Range of largest group in tract by MixedMetro category, pooled for 1990, 2000, 2010

The standard deviations capture the bulk of the distributional ranges but not their full extent. This table shows the minima, maxima and several percentile values (10th, 25th, 50th, 75th, 90th) for the largest group in each category. For low and moderate diversity tracts, the largest group corresponds to the referenced group in the category name. In high diversity tracts the largest group can be any group.

In low diversity tracts, the minima and medians (p50) are high. In moderate diversity tracts, the medians are in the mid 50% to mid 60% range (near or just below the value of the minima in the equivalent low diversity category) except for moderately diverse Other tracts of which there is only one.

The minima for largest group size in moderately diverse tracts can fall below 50%, dropping to as low as 31.2%, for example, in the moderately diverse White case. These cases are relatively rare, however: in 90% of moderately diverse tracts the largest group has a 41.2% or greater share of the tract population (the 10th percentile for moderately diverse Asian (MDA) tracts), excluding the singular moderately diverse Other (MDO) tract. The 25th percentile indicates that 75% of all moderately diverse tracts (again excluding the moderately diverse Other single tract case) have at least a 45% share for the largest group.

Category Min p10 p25 p50 p75 p90 Max
LDW 0.62275 0.82873 0.87525 0.93140 0.96734 0.98370 1.00000
LDB 0.62037 0.80391 0.85462 0.92261 0.96648 0.98266 1.00000
LDL 0.64432 0.80037 0.83060 0.88178 0.93558 0.96708 1.00000
LDA 0.72222 0.80399 0.81348 0.84175 0.88286 0.91061 1.00000
LDNA 0.63407 0.79333 0.84624 0.91614 0.95644 0.97365 1.00000
MDW 0.31237 0.49220 0.56290 0.65937 0.73500 0.77424 0.79995
MDB 0.32437 0.46130 0.51263 0.58468 0.67414 0.73887 0.79991
MDL 0.31268 0.43850 0.49541 0.57532 0.66734 0.73642 0.79994
MDA 0.32314 0.41243 0.46145 0.53832 0.64837 0.73113 0.79946
MDNA 0.35739 0.46380 0.51745 0.60418 0.69481 0.74519 0.79725
MDO 0.38762 0.38762 0.38762 0.38762 0.38762 0.38762 0.38762
HD 0.25335 0.31267 0.33946 0.37032 0.40067 0.42349 0.44979

Minima and maxima of entropy and share of all groups by MixedMetro category, pooled for 1990, 2000, 2010

This table illustrates the maxima and minima for entropy and the share of all groups in each category. For the shares, the minima and maxima of the largest group correspond to the values in the previous table.

The entropy data show an entropy maximum for low diversity categories that exceeds .3707 because a small proportion of low diversity tracts are assigned to this category based on having a largest group that exceeds 80% of the tract population share. Similarly, moderate diversity tracts can exceed the threshold for high diversity of .7414 because a fraction of these tracts have their largest group exceed 45% of the tract population.

Minima

Category Entropy White Black Latino Asian NatAm Other
LDW 0.00000 0.62275 0.00000 0.00000 0.00000 0.00000 0.00000
LDB 0.00000 0.00000 0.62037 0.00000 0.00000 0.00000 0.00000
LDL 0.00000 0.00000 0.00000 0.64432 0.00000 0.00000 0.00000
LDA 0.00000 0.00000 0.00000 0.00000 0.72222 0.00000 0.00000
LDNA 0.00000 0.00000 0.00000 0.00000 0.00000 0.63407 0.00000
MDW 0.37073 0.31237 0.00000 0.00000 0.00000 0.00000 0.00000
MDB 0.37071 0.00000 0.32437 0.00000 0.00000 0.00000 0.00000
MDL 0.37082 0.00000 0.00000 0.31268 0.00000 0.00000 0.00000
MDA 0.37116 0.01172 0.00000 0.00000 0.32314 0.00000 0.00000
MDNA 0.37084 0.05400 0.00000 0.00000 0.00000 0.35739 0.00000
MDO 0.69882 0.35545 0.09257 0.16436 0.00000 0.00000 0.38762
HD 0.74143 0.01389 0.01325 0.01427 0.00000 0.00000 0.00000

Maxima

Category Entropy White Black Latino Asian NatAm Other
LDW 0.44123 1.00000 0.37638 0.37725 0.35398 0.37500 0.11721
LDB 0.41971 0.37346 1.00000 0.37963 0.15953 0.05594 0.06250
LDL 0.43703 0.35897 0.33060 1.00000 0.24901 0.09933 0.04138
LDA 0.40888 0.26667 0.05526 0.17690 1.00000 0.01575 0.02594
LDNA 0.37010 0.36593 0.06935 0.23475 0.02105 1.00000 0.01149
MDW 0.81129 0.79995 0.49874 0.49772 0.47249 0.48040 0.34555
MDB 0.80442 0.49981 0.79991 0.49047 0.42477 0.40299 0.34668
MDL 0.79270 0.49683 0.49094 0.79994 0.45981 0.39298 0.11769
MDA 0.79951 0.48161 0.47296 0.46645 0.79946 0.10974 0.14444
MDNA 0.73697 0.48626 0.41502 0.40772 0.16371 0.79725 0.14228
MDO 0.69882 0.35545 0.09257 0.16436 0.00000 0.00000 0.38762
HD 0.92121 0.44979 0.44863 0.44971 0.44686 0.43416 0.31568

  1. Holloway, S. R., R. Wright, and M. Ellis. 2011. The Racially Fragmented City? Neighborhood Racial Segregation and Diversity Jointly Considered. The Professional Geographer 64 (1):63–82.