Nineteenth Century Population
Why did mortality decline?

Professor Thomas Mckeown's Modern Rise of Population was published in 1976, summarizing over two decades of painstaking empirical work, applying the insights of medicine and epidemiology to a historical analysis of Britain's detailed national series of death records. This work revolutionized medical and demographic history, overturning a long-standing view regarding the importance of medical advances in bringing about the decline in mortality which accompanied industrialization in Britain. Mckeown effectively demonstrated that advances in medical science, such as the immuno- and chemotherapies which form the basis of today's clinical and hospital practices, played only a very minor role in the late nineteenth century mortality decline: most of the important diseases involved had already disappeared in England and Wales before the date at which the relevant medical innovations occurred.

In addition to this negative finding, Mckeown claimed that his analysis of the epidemiological evidence showed that the major influence on the decline in mortality was a steady rise in 'living standards' and the associated rise in average nutritional intake. Mckeown also identified 'municipal sanitation' and 'hygiene improvements' as a positive but very much secondary factor, which only assumed importance during the last third of the nineteenth century. This 'nutritional determinism' ascribed improvements in the health of the nation to rising living standards, with a reduced incidence of respiratory tuberculosis (t.b.) the most important epidemiological feature.

Mckeown's conclusions have achieved broad general acceptance and the importance of rising living standards is now taken for granted in much research on the mortality decline in Victorian and Edwardian Britain. In this respect Britain is an exceptional case, in that neither medical science nor public health practices are judged to have been as important as they seem to have been in other countries. In Discussion Paper No. 121, Research Fellow Simon Szreter examines Mckeown's arguments, and in particular his assertion that rising living standards and improved nutrition should be regarded as the major cause of falling mortality in Britain during the period 1850-1914.

Szreter first examines the epidemiological evidence, and in particular the role of t.b.. It is essential, he argues, to recognize the interrelations between different diseases. For example, the presence of t.b. impedes an individual's capacity to resist other diseases, so that the prior decline in t.b. detected by Mckeown would be expected to facilitate the reduced fatal incidence of other diseases. On the other hand, t.b. generally takes a lethal hold when an individual has already been weakened by another disease, so that any decrease in the incidence of other diseases would probably have a secondary effect of reducing the number of t.b. victims. The chronology of the declines in various lethal diseases is therefore a crucial element of any analysis of falling mortality, Szreter argues.
Using Mckeown's own evidence, Szreter challenges his argument that the reduced incidence of respiratory tuberculosis accounted for nearly half of the decline in mortality rates in this period. The incidence of lethal bronchitis, he observes, rose anomalously by 20%. This appears to contradict Mckeown's view that a general fall in airborne diseases was the principal epidemiological change during the nineteenth century. On the other hand, it is plausible that changes in certification accounted for this rise in reported lethal bronchitis, offsetting the fall in reported t.b. death rates.

These arguments suggest that it is no longer plausible to argue, as did Mckeown, that a sustained fall in fatalities from the airborne diseases began in the 1840s, predating and making possible the later declines in mortality from the 'sanitation' diseases. Instead, Szreter detects no clear trend towards declining t.b. until the late 1860s, making falling death rates from t.b. no more important a contributor to decreasing mortality overall than the falling rates from water-borne diseases such as typhus and typhoid fever or food-borne diseases such as cholera and diarrhoea.

Szreter suggests an alternative interpretation based on a wider view of trends in national average life expectancy at birth. Although for nearly a century after the 1730s life expectancy had risen steadily, from under 30 to just over 40 years, it remained stationary through the middle quarters of the 19th century, before rising to 47-8 years by 1900 and just over 60 by 1931. This plateau in life expectancy, which did not emerge in Mckeown's analysis, coincided with the most rapid and intense phase of urbanization. Szreter argues that the unprecedented and unplanned growth of overcrowded cities lacking proper water supply and waste disposal facilities was directly reflected in the increasing incidence of the sanitation diseases in the first two thirds of the nineteenth century. This theory is supported by regional variations in life expectancy. For example, in 1840 average life expectancy at birth was 45 years in rural Surrey, but only 26 years in Liverpool, which had trebled in size in 40 years.

Yet real wages in urban centres generally rose in this period, undermining the primary role accorded to living standards by Mckeown in determining mortality trends. Moreover, Szreter argues that the return to generally declining mortality in the last third of the nineteenth century reflects the chronology of the most significant improvements in public health and urban sanitation. In the 1870s, the establishment of the Local Government Board and the passing of a series of Public Health Acts introduced a period in which local authorities took on an increasing role in safeguarding public health. The majority of urban authorities took over the function of supplying water. A wide range of preventive measures were implemented throughout the country, governing municipal sanitation, the content of food, and the urban environment, particularly overcrowding. The elimination of typhoid and cholera, Szreter argues, testifies to the effectiveness of large-scale preventive health measures.
This reinterpretation suggests that mortality decline was the result of human agency, in the form of expanding preventive public health provisions and services, rather than the result of an impersonal invisible hand of rising personal 'living standards'. Yet, Szreter notes, the direct effects of improved public health and municipal sanitation on mortality indices cannot as yet be demonstrated conclusively, and future research could profitably investigate this aspect of the mortality decline.


The Importance of Social Intervention in Britain's Mortality Decline c. 1850-1914: A Reinterpretation
Simon Szreter

Discussion Paper No. 121, August 1986 (HR)