Regional and Racial Inequality in Infectious Disease Mortality in U.S. Cities, 1900-1948

Abstract

In the first half of the twentieth century, the rate of death from infectious disease in the United States fell precipitously. Although this decline is well-known and well-documented, there is surprisingly little evidence about whether it took place uniformly across the regions of the United States. We use data on infectious disease deaths from all reporting U.S. cities to describe regional patterns in the decline of urban infectious mortality from 1900 to 1948. We report three main results. First, urban infectious mortality was higher in the South in every year from 1900 to 1948. Second, infectious mortality declined later in southern cities than in cities in the other regions. Third, comparatively high infectious mortality in southern cities was driven primarily by extremely high infectious mortality among African Americans. From 1906 to 1920, African Americans in cities experienced a rate of death from infectious disease that was greater than what urban whites experienced during the 1918 flu pandemic.

Keywords: Economic history; Epidemiological transition; Inequality; Infectious disease; Mortality.

Figure A.1:

Standard Age Schedule of Infectious Mortality Used to Indirectly Standardize Mortality Rates, in Bold, Shown with the Schedules for Other Years for Comparison. Infectious rates are shown in deaths per 100,000.

Figure A.2:

Logged, Age-Standardized Mortality in U.S. Cities by Region, Classifying Rheumatism and Rheumatic fever as Infectious. Infectious mortality is standardized to eliminate variation in the age distributions of cities. The trend lines depict the logged ratio of actual to expected infectious mortality, based on the city’s age distribution.

Figure A.3:

Number of cities, by year and region, in each data panel.

Figure A.4:

Location of Cities in Sample by Region, in Each Data Panel.

Figure 1:

Infectious Mortality, Standardized and Unstandardized, in U.S. Cities by Region. In 1a, we report regional medians of mortality rates per 100,000. In 1b and 1c, infectious mortality is standardized to eliminate variation in the age distributions of cities; the trend lines depict the logged ratio of actual to expected infectious mortality, based on the city’s age distribution.

Figure 2:

Logged, Age-Standardized Infectious Mortality in U.S. Cities by Region. Infectious mortality is standardized to eliminate variation in the age distributions of cities. Each dot represents the logged ratio of actual to expected infectious mortality in one city in one year, based on the city’s age distribution. We plot the median city in each year using darker dots. We draw linear trends within five periods. Each period is defined as a set of years during which the cause of death categories are relatively stable. We omit 1918–1920 to avoid distortions from the flu pandemic.

Figure 3:

Estimated Region Fixed Effect and Year Effect Coefficients. We fit separate regressions for each time period, allowing the year effect to differ across regions. The regression outcome is logged, age-standardized infectious mortality, representing the logged ratio of actual to expected infectious mortality, based on the city’s age distribution. We plot 95% confidence intervals from the regressions around each coefficient, clustering standard errors at the city level.

Figure 4:

Logged, Age-Standardized Infectious Mortality in U.S. Cities by Region. Infectious mortality is standardized to eliminate variation in the age distributions of cities. The trend lines depict the logged ratio of actual to expected infectious mortality, based on the city’s age distribution.

Figure 5:

Proportion of Excess Southern Infectious Mortality Explained by the Greater Nonwhite Population Share in the South.

Figure 6:

Logged Age-Standardized Infectious Mortality in U.S. Cities by Region. The dashed line indicates median infectious mortality during the 1918 flu pandemic among urban whites in cities present in the data for at least 30 years (1.156). Because there are an even 52 cities in this sample, the median is the midpoint between 1918 white infectious mortality in Memphis, TN (1.149) and in Mobile, AL (1.163). Each line represents a city in our sample. We limit the sample to cities reporting mortality for whites and nonwhites in at least 30 years.