The term “slum,” probably originating from an old English or German word meaning a poorly drained or muddy place, was applied to housing in the early Industrial Revolution in the United Kingdom before the railways were in place, when canals transported heavy goods along the length and breadth of the country. During Britain’s rapid industrialization, most factories were built beside canals, the main channel for transporting coal for their steam engines and other inputs of production.
Poor workers, migrating to cities for factory jobs, could ill aff ord to walk long distances to and from their places of work. Before electric trams, other forms of transport were expensive. So workers settled close to factories. Cheap housing grew around these factories in low-lying, poorly drained areas. Housing was overcrowded.
Sanitation was inadequate and in most cases nonexistent. And air quality was poor, with soot and other pollutants. Sickness was commonplace. Diarrhea, typhus, respiratory diseases, measles, and scarlet fever cut the life expectancy of those born in cities by 12 years compared with those born in rural areas. The growing public health hazards in Britain’s urban slums exacted a terrible health toll that eventually reached out beyond the working class, finally motivating strong political action. But rather than attempting to stop more workers from coming, or clearing out these areas of disease and poverty, the government in the 1870s passed legislation for strict building regulations, prescribing the dimensions of streets and houses, and making it mandatory that all dwellings be connected to newly built sewerage systems. Major municipal investments in water works, sewage facilities, and public health dramatically reduced mortality in Britain’s cities between 1874 and 1907.
Despite atrocious and filthy conditions, millions of migrants keep leaving rural areas for the teeming economic opportunity off ered in the cities of poor and middle-income countries. Even though health hazards and mortality rates are far worse in the shanties around many cities in Africa, people there are trading, working, and sending large sums of money home.
The challenge facing policy makers today is similar to that faced by the Victorians in London: how to nurture these agglomerations with functional land markets, better transport, and public health infrastructure to capture the benefi ts of economic growth.
Sources: Satterthwaite and others 2007; Crafts 2008; The Economist 2007a.

