Demography, Disease, and Development: An Evolutionary Approach

Abstract

Emphasising the impact of diseases on history, the essay integrates demography, economics, evolutionary theory, and microbiology to explain the historical development of humanity and the economy, with specific application to American economic development prior to the twentieth century. The cultural development of prehistoric humanity is explained with simple demography in which the blooming of Paleolithic culture about 50,000 years ago also induced diseases of permanent settlements. A model of historical long-run growth incorporates transportation developments with cycles; one “virtuous” (expanding markets and specialisation), the other “vicious” (spread of diseases with increased trade). The New World conquest is viewed as almost entirely due to microbiology, evolutionary selection, and environmental conditions (climates and soils) as was the eventual peopling of different New World regions. American economic development prior to the twentieth century is considered the result of primarily demographic changes, transportation developments, and large-scale plantation slavery that combined to spread infectious diseases. This has implications for American economic development, Malthusian Doctrine, and issues of environmental degradation and sustainability.

Keywords:

• demography
• diseases
• development
• population growth
• parasites
• growth
• evolution
• human history
• slavery
• American development
• American economic history
• microbiology
• disease susceptibilities
• pathogens

JEL classification:

• O15
• O44
• I15
• J10
• N31

Notes

²For examples of technological regression in small populations, see Diamond 1997, 53–66, 253, 256–57.

³The quotation marks around sustainability are there because it is not clear what the proponents of doctrinal belief in sustainability mean. It appears that advocates of sustainability believe that resources are finite and current rates of usage are unsustainable because they will be used up in the foreseeable future; advocates appear to believe that higher living standards for larger populations are both unsustainable and undesirable because resources are finite and the environment is degraded.

⁴For example, drinking beverages with boiling water or with an alcoholic content of 4 percent (or more) were effective ways of avoiding the water-borne pathogens that came with permanent settlements. Preferences for these beverages developed in various societies and were more likely to be culturally transmitted to descendants; dead people cannot tell their children to drink water.

⁵High death rates during famines are typically caused by people migrating to where they perceive food is in greater abundance. Large numbers of people congregate and infectious diseases spread; people typically die of infectious diseases not insufficient nutrition (see Livi-Bacci 1991, 1992).

⁶Note the paradoxical role of increased income in the transmission of diseases. Increased income led to an increase in demand for both more food and “higher quality” foods derived from animals; this led to a more than proportional increase in the demand for animal products, which in turn led to a more than proportional increase in the urban biomass available to disease-causing microbes as animals, plant foods, and their waste products increased.

⁷The disease environment in the tropics was more virulent than other regions. Most cold-weather diseases, while they do not thrive in warm climates, can exist for years in the human populations in the tropics since they do not kill quickly as their reservoirs tend to be in human populations. Consequently, if they are quickly fatal, the pathogens will not survive for long. As long as they are intermittently reintroduced, cold-weather pathogens will exist. As a result, the New World tropics were subject to a great variety of endemic warm-weather diseases given its climate and the periodic episodes of cold-weather diseases. In the non-tropical New World, warm-weather diseases did occur, but there were fewer and they were less virulent.

⁸The number of urban places is from Carter et al. (2006, vol. I, series Aa684–98, 1–102). The percentage of population urban is calculated from series Aa2, 1–26, and note 1 and series Aa699, 1–104 in Carter et al. (2006, vol. I).

⁹For transport costs and times, see Haites, Mak, and Walton (1975, 32), Mak and Walton (1972, 630, table 2, and 639, appendix table II), and Taylor (1962, appendix A, table 2), cited in Atack and Passell (1994, 148 and 157, tables 6.1 and 6.3, respectively).

¹⁰The cause-specific mortality rates discussed in this paragraph can be found in McGuire and Coelho 2011, ch. 7, 188–204 and in appendix C, 235–73.

¹¹For example, historians who have studied the centuries that encompass the period of global cooling in the Northern hemisphere known as the Little Ice Age (circa 14th century to circa mid-19th century) have been seduced by its gradualness. The evolutionary changes in climate, agriculture, and diseases during the Little Ice Age were so gradual as to be invisible to those experiencing them, and they remain invisible in our histories. Clark (2007), for instance, ignores the effects of evolutionary changes in the economic history of England; his reliance on agricultural real wage data as a proxy for living standards is unfortunate because the data are neither corrected for changing climate nor for the changing levels of morbidity in the agricultural workforce. An assumption that these do not change much year to year is tenable; the assumption is not tenable over centuries. It defies all we know about agriculture to suggest that the Little Ice Age had no effect on labour productivity.

Additional information

Notes on contributors

Robert A. McGuire

This essay borrows freely from McGuire and Coelho 2011 with permission.