The Social Geography of Drug Use in Metropolitan Los Angeles


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Analysis of Drug Treatment Facilities

The Los Angeles County Department of Health Services‘ Alcohol and Drug Program Administration (ADPA) published its 2002-03 fiscal report, reviewing the 122 Alcohol and Drug (AOD) programs contracted by the LA County ADPA to provide services to 45,747 participants (APDA, 2003, p. i). Participants were identified by the Service Planning Area (SPA) in which they were resident. A SPA is one of eight divisions used by Los Angeles County to provide health care. The following set of maps accounts for the distribution of participants by SPA.

Participants in Drug and Alcohol Programs
This map displays the distribution of participants through the SPAs. We see that a general pattern of concentration is not immediately obvious. This is likely mostly due to the unwieldy large nature of SPAs. They agglomerate small and disparate census block groups. However, the South and San Gabriel SPAs could be termed ‘hot spots’, with greater numbers of participants located there. On the other end of the continuum lie the West and Antelope Valley SPAs.

Percentage Participatipon in Drug or Alcohal Programs
However, when mapping percentage of population involved in an AOD Program (number of participants divided by total population within a SPA), the severity of the situation is mitigated in a few SPAs. Comparing this map with the preceding map reveals that Antelope Valley’s smaller population actually shows evidence of a larger proportion of people receiving treatment from an AOD Program. South is still a major node of high participation in AOD programs, but in this map there is also a strong correlation of distance from the South SPA and decline in AOD participation, with Metro and East SPAs showing a greater concentration, per capita, than in the previous map. However, an anomaly in this pattern is the West SPA, with the lowest per capita participation, 0.19% of population, in AOD treatment programs.

Participants per Caipta and Median Income
This map compares the median incomes of each SPA, considering standard deviations along a normal distribution. It assists the interpretation of the preceding map, the distribution of participants receiving AOD treatment, in light of the socioeconomic situation of each SPA. A general relationship between participation in AOD programs and median income is discernible. SPAs at or below the mean median income tend to exhibit higher numbers of program participation, even when calculated as a percentage of population. A linear regression analysis of the data confirms the negative correlation between income and drug treatment participation per capita, with an r-squared value of 0.67.

However, this map underscores the high degree of AOD program participation in Antelope Valley, uncharacteristic given its apparently average socioeconomic status. However, it lies in the middle of an income range that includes SPAs reporting very high incomes. For example, Pacific Palisades, a community within the West SPA,reported a median household income of $131,614 in 2000. Compared to the state average of $68,130, this illustrates the relative economic stability of Antelope Valley. That is, though Antelope Valley appears "average," this statistic is relative to one of the wealthiest geographic units in the United States.

Distributions of Treatment Facilites and Participants (% of Population)
The AOD Programs contracted by the Los Angeles Department of Health to provide treatment are concentrated around the South and Metro SPAs, which is highly appropriate given the concentration of need there. It is notable that East has fewer treatment facilities than West, despite the higher percentage of East’s population needing those facilities.

Overall, though, these facilities appear to cluster near one another, which decreases their accessibility for people who do not live near them. This may decrease the likelihood of people receiving care from these programs, which is detrimental to the advancement of health care outcomes for people with AOD problems.

A Brookings Institute report titled "Access to Social Services: The Changing Urban Geography of Poverty and Service Provision" (Allard, 2004) found that in Chicago, Washington, DC, and Los Angeles, "[census] tracts with higher poverty rates are located in closer proximity to social service providers than tracts with lower poverty rates. On average, tracts with low poverty rates are within 1.5 miles of one-third, one-fifth, and one-quarter as many providers in metropolitan Chicago, Washington, D.C., and Los Angeles respectively, as tracts with high poverty rates" (ibid). This is supported by our geostatistical findings illustrated in the map above.

Income and Drug Treatment Facilities
This map shows the locations of drug treatment facilities, and median income at the census block group level. At this finer resolution, the distribution of drug treatment centres follows a similar pattern. Treatment facilities tend to be situated in low-income neighbourhoods, where there is presumably the greatest need for them. Spatially, these facilities align loosely with "belts" or "corridors" of census block groups with lower-than-mean income levels. These "corridors" radiate outward from the city centre.
Again, the map demonstrates the spatial clustering of treatment facilities. The distance to the nearest treatment facility grows larger as one moves away from the central business district. Several large neighbourhoods, notably in West Los Angeles, the southeastern edge of the county, and the northeastern foothills, contain no drug treatment facilities at all.

Number of Treatment Programs and Median Age
We see that there is no salient connection between median age and AOD program participation. The extremes of South (youngest median age, highest program participation) and West (oldest median age, lowest program participation) are immediately noticeable, but the correlation is not supported by the six SPAs in between those extremes, where age and program participation seem fairly independent of one another.

Drug-related Crime

In December 2002, the Narcotics Division of the Los Angeles Police Department published its first annual statistical report of drug-related arrests and narcotics seizures within the City of Los Angeles. This data is summarized by the number of arrests, the type of narcotic, and the total street value seized by authorities.
The jurisdiction of the LAPD is divided into nineteen operational units called "police communities." The statistics from the Narcotics Division are divided by police community and allow for spatial comparison.

Income and Drug-Related Arrests
This map displays both the number of drug-related arrests in each police community and the median income of each community. Median income is represented considering standard deviations along a normal distribution.
While the West Los Angeles community has the highest median income and the fewest total number of drug-related arrests, the Central community displays the lowest median income and the highest total number of drug-related arrests. Remaining communities fall somewhere in between these two extremes on both variables.
In addition, a general east-west pattern of increasing income is present.

Income and Drug-Related Arrests per 1000 Persons
When corrected for population, the relationship between socioeconomic status and drug-related arrests is clearer. This map displays median income along the same scale, but normalizes drug-related arrests by dividing by their total number by the population of each community.
This map shows that drug-related arrests per capita are highest in the Central community, where the number of drug-related arrests is equal to almost 6 percent of the area’s population. Communities near Central, especially those below the mean income of the city as a whole, also display higher than average drug-related arrests per capita.
Through statistical linear regression analysis, a weak statistical correlation emerges between income and drug-related arrests at the community level (r-squared value = 0.20). The Central community emerges as a significant "hot spot" for drug-related activity, having the most drug-related arrests per capita by a factor of five. Because this community is a major outlyer, skewing the linear model sharply (see graph), we decided to perform the regression model again, this time excluding Central. Among the other 18 communities, the r-squared value increases to 0.37.
Thus, the frequency of drug-related arrests in Los Angeles is shown to be related to both income (but only weakly) and geographical proximity to the city centre (with residuals increasing in outlying communities).

Income and Drug Arrests by Type
This map attempts to reveal drug use trends in higher and lower socioeconomic classes by showing the distribution of drug-related arrests by drug type.
The community with the highest median income, West Los Angeles, saw a high proportion of drug arrests related to marijuana and heroin, and a smaller proportion of arrests related to cocaine. No other types of drug were involved in arrests.
Contrarily, in communities with low median incomes, and especially Central, most drug-related arrests were related to cocaine. Marijuana-related arrests generally accounted for a smaller percentage of arrests in these areas.
Any other trends are masked by the overwhelming prevalence of undefined, "other" narcotics in middle-class communities. The percentage of arrests related to "other" drugs increases in communities farther from the city centre.