Since the early decades of the 20th century, localities with youth gang problems have shared a set of distinctive characteristics. Some of these characteristics, as shown in previous chapters, were affected by major changes between 1970 and 1995. One important change involves the size of gang-problem cities. Prior to the 1970's, gangs were most likely to be found in the largest cities and were generally absent in cities with populations of less than 100,000. This chapter explores 25-year changes in the size of gang cities.

Most gang surveys have limited their coverage to the Nation's larger cities. To achieve the greatest possible coverage for both earlier and later decades, this chapter uses the definition of "city" developed by the Municipal and Township Governments section of the U.S. Department of Commerce, Bureau of the Census, which counts those municipal and township units that have local governments. Data for governmental units by population categories are available both for the 1970's (about 35,500 municipal and township units) and 1990's (about 40,000 units). Using this definition ensures that cities and towns will not be ignored if they are small, and indeed subsequent tables show that towns with populations of less than 1,000 constituted more than half of all municipal and township units in both the 1970's and 1990's.¹⁶

Gang Cities, by Population Category

Table 18 assigns the gang cities of the 1970's and early 1990's to 11 population categories, but the peaks of the curve fall in different places in the two periods.¹⁷ In the 1970's, the population category with the highest percentage of gang cities—about 25 percent—was the 50,000 to 99,000 category. By 1995, the peak category had fallen to smaller cities, those in the 25,000 to 49,000 level, with about 27 percent of all cities this population range. This reflects an increase in the number of smaller cities reporting gang problems—a major trend illustrated more clearly in table 19.

Table 19 addresses the question "What percentage of gang cities fell below designated population levels in the 1970's and 1995?" Ten levels are distinguished, ranging from 500 to 1 million. For example, in the 1970's, 188 of 201 cities, or 94 percent, had populations smaller than 500,000 while in 1995, 1,456 out of 1,479 cities, or 98 percent, had populations below 500,000. The percentage of gang cities at each population level was lower in the 1970's than in 1995, but the major differences were found at the 25,000 level and below. At the 25,000 level, percentages for the 1970's and 1995 stood at about 29 and 42 percent, respectively. For cities with populations smaller than 10,000, the percentage was about 6 percent in the 1970's compared with about 20 percent in 1995, and at the 5,000 level, 2 percent and 9 percent, respectively. Thus, by 1995, almost 1 in 5 gang cities had a population of 10,000 or less, compared with about 1 in 15 in the 1970's; and almost 1 in 10 had populations of less than 5,000, compared with about 1 in 50 in the 1970's.¹⁸

* Populations were not available for eight cities.

* Total number of gang cities=201.
Total number of gang cities=1,479 (populations were not available for eight cities).

Population Categories: Gang Cities Compared With All U.S. Cities

In addition to gathering information on the numbers and percentages of gang cities in different population categories, it is important to compare the figures for gang cities with the figures for all U.S. cities and to trace the changes in each population category during the 25-year study period. Tables 20 and 21 compare the numbers and populations of gang cities in the 1970's and 1990's with the numbers and populations of all cities.

Note: "Cities" in this table includes U.S. cities and towns with municipal or township governments.

Sources: Data on numbers and populations are from Statistical Abstract of the United States, 1974, table 420, "County, Municipal, and Township Governments, 1972, and Their Population, 1970, by Population Size Groups" (p. 262); and Statistical Abstract of the United States, 1995, table 473, "County, Municipal, and Township Governments, 1992" (p. 298). Both documents were published by the U.S. Department of Commerce, Bureau of the Census, in Census of Governments, Vol. 1, Governmental Organization.

As shown in the chapter entitled "Gang Localities in the United States: A Quarter-Century Summary," less than 1 percent of all cities, or about 200 out of 35,000, reported gang problems in the 1970's. Table 20 breaks down the all-city totals for the 1970's into separate population categories to show that the percentage of gang cities at specific population levels differed substantially. Almost 28 percent of the 180 cities with populations of more than 100,000 reported gang problems, about 16 percent for populations of 50,000 to 100,000, and 7 percent for populations of 25,000 to 49,000.

Note: Data for the 1990's cover the period 1990-95. "Cities" in this table include U.S. cities and towns with municipal or township governments.

* Populations were not available for eight cities.

Sources: Data on numbers and populations are from Statistical Abstract of the United States, 1974, table 420, "County, Municipal, and Township Governments, 1972, and Their Population, 1970, by Population Size Groups" (p. 262); and Statistical Abstract of the United States, 1995, table 473, "County, Municipal, and Township Governments, 1992" (p. 298). Both documents were published by the U.S. Department of Commerce, Bureau of the Census, in Census of Governments, Vol. 1, Governmental Organization.

Comparing the number-based with the population-based totals shows that cities constituting 21 percent of the all-city population reported gang problems, compared with the number-based figure of less than 1 percent. Most of this difference, however, was accounted for by gang cities with populations of 100,000 or more, where cities constituting 51 percent of the national city population reported gang problems, compared with 28 percent for the number-based figure.

Table 21 displays the same kind of information for the 1990's as table 20 presents for the 1970's. The differences between the two time periods are striking. Data in table 20 indicate that in the 1970's, cities with populations of 10,000 or more accounted for 94 percent of all gang cities; by the 1990's, as shown in table 21, data indicate that this figure had fallen to 79 percent. In the 1970's, as shown in "Gang Localities in the United States: A Quarter-Century Summary," the population of cities reporting gang problems was about one-fifth of the all-city population; by the 1990's, the population of gang cities had risen to more than one-half of the Nation's all-city population.

The highest percentage figure in the 1970's table is 50.8 percent—the gang-city population as a percentage of the all-city population—while the equivalent figure for the 1990's is 92 percent. The number-based percentages for the top three population categories of gang cities as a percentage of all U.S. cities in the 1970's range from about 7 to 28 percent, compared with a range of 49 to 86 percent in the 1990's. The population-based figures for the top three categories—the total gang-city population as a percentage of the all-city population—range from 7 to 51 percent in the 1970's (table 20) compared with a range of 50 to 92 percent for the 1990's.

Figures 18 and 19 display the number-based data in tables 20 and 21 to compare the prevalence of gang cities in the 1970's and the early 1990's. The two figures use different measures to focus first on larger and second on smaller cities.

Note: Data for the 1990's cover the period 1990-95.

Figure 18 displays the percentage of cities in each of the eight population categories that reported gang problems in the 1970's and 1990's. For example, for cities with populations of 100,000 or more, 28 percent reported gang problems in the 1970's compared with 86 percent in the 1990's. For cities with populations between 10,000 and 24,000, 3 percent reported gang problems in the 1970's compared with 16 percent in the 1990's. The graph shows that while increases in gang problems occurred at all population levels, the most obvious increases appeared in the top four population categories. In these four categories, the larger the city, the greater the increase. Subtracting the 1970 percentages from the 1990 percentages shows an increase of 58 percentage points for cities with populations greater than 100,000; 54 points for populations between 50,000 and 100,000; 42 points for populations between 25,000 and 49,000; and 13 points for populations between 10,000 and 24,000. The scale of the graph obscures the magnitude of change for populations of less than 10,000 because their numbers are too small to affect observable comparisons.

Figure 19 clarifies the nature of growth among the smaller cities as measured by the magnitude of change statistic used frequently in earlier chapters. The graph shows how many times the number of gang cities increased between 1970 and 1995 in each of eight population categories.

* The magnitude of change is the number of gang cities in 1995 divided by the number of gang cities in the 1970's.

For example, in the "more than 100,000" category, the number of gang cities increased from 50 to 195, or about 4 times (see tables 20 and 21); in the 5,000 to 9,000 category, the number of gang cities increased from 8 to 158, or about 20 times. The graph shows clear differences between cities in the larger and smaller categories. Between the 1970's and 1995, cities in the four higher categories (populations 10,000 or greater) show increases ranging from 4 to 9 times; cities in the four lower categories (less than 10,000) show increases of 15 to 41 times. The 41-fold increase shown by cities in the 1,000 to 2,400 category makes this change higher than all the changes shown in figure 7 except one, falling just below South Atlantic cities in the ranking of localities by magnitude of change. One reason for the higher magnitude of change for the smaller cities is essentially statistical; the fact that there were relatively few smaller cities in the 1970's produced larger change figures than if there had been more smaller cities.

In summary, data show that the numbers, populations, and long-term trends of gang cities varied significantly according to size of population categories. Both large and small gang cities showed substantial increases between the 1970's and 1990's, with growth trends of larger cities most prominent when differences between percentages were measured and growth trends of smaller cities most prominent when the magnitude of change measure was used.