Measuring small towns – why definitions matter?
Small towns are where a large proportion of the world’s urban population live, and where the boundary between what is urban and what is rural is blurred. But definitions matter as they determine the allocation of resources.
A small junction town on the Kabale-Mbarara Road, near Kandago, Uganda (Photo: Adam Cohn, via Flickr, CC BY-NC-ND 2.0)
The transition to an urban world is linked to profound rural transformations. Currently, a large proportion of people in low- and middle-income countries live in small towns. They may move between different locations, relying on very diversified income sources that combine farming, industry and services.
This challenges the view of a neat urban-rural divide. It also calls for a better understanding of urbanisation dynamics beyond large and intermediate centres.
As the growth of smaller urban centres is projected to be an important contributor to urbanisation in Africa and Asia, these centres will play a crucial role in facing new local and global challenges.
These include the ability to provide basic services and infrastructure to their growing populations and those of their surrounding rural areas, supporting the creation of employment for a youthful and mobile labour force that often includes displaced people, and adapting to the impacts of the climate and ecological crisis while playing a growing role in managing local natural resources.
The definitions used to classify settlements are critical in determining the allocation of resources. To fulfil their functions, urban centres need financial resources and technical capacity. This is especially important for small towns as they ‘graduate’ from large village to urban centre. But what makes a settlement ‘urban’?
How to define and measure what is urban?
Population distribution between urban and rural areas varies substantially between regions and over time, and so do national definitions of what constitutes an urban centre.
Criteria range from administrative status, as for example in Egypt and India, to population size which in turn can range from 50,000 in Japan to 200 in Iceland, to the density of the built-up area, and to the share of non-agricultural employment of its residents.
While there are significant differences in national definitions of urban centres, in most cases they include settlements with a population of at least 20,000. This leaves out a substantial proportion of centres – small towns and large villages – limiting the validity of international comparisons.
To complicate things further, definitions often change over time. For a flavour of this complexity see the accompanying notes in the UN’s latest published 'Demographic Yearbook for 2022' (pages 186-190).
There are also many exceptions in definitions of urban centres linked to political decisions rather than demographic data. In China, the pervasive ‘urban villages’ are densely developed areas often well within the built-up area of existing cities, but they remain under rural governance systems as this allows city governments to avoid paying compensation to their residents.
In many low-income countries there is also a lack of recent census data, often due to the cost of collection, which means that urbanisation figures are the result of projections of original data – sometimes collected decades ago.
This can have seriously distorting impacts. Limited census frequency and the resulting reliance on projections have led to misplaced analyses of urbanisation in Africa, as it was impossible to consider how worsening economic conditions affected urbanisation dynamics.
Towards more consistent definitions?
It would obviously be helpful to have consistent definitions of what is meant by an urban centre. It would make urbanisation dynamics easier to understand, and support adequate policies.
Recent attempts to standardise definitions include the Degree of Urbanization (DEGURBA) methodology endorsed by the UN Statistical Commission. This is based on geospatial population data and defines settlements based on their population density. But the estimates it has produced have proved to be controversial, largely because it uses density thresholds of at least 300 inhabitants per km2 and a minimum population of 5,000.
These are appropriate measures for the European context, for which it was initially developed, but work less well in low- and middle-income countries. The result is an over-counting of smaller settlements in densely-populated rural districts in countries such as Malawi and Rwanda, where compact agglomerations of smallholder farmsteads with clear rural socio-economic characteristics might be mistakenly classified as ‘urban’.
Especially in Africa, where small towns form the majority of urban settlements, improving their measurement is of critical importance for developing appropriate urban policies and allocating sufficient resources. However, collecting detailed data on demographic and economic activities is often beyond the financial and technical capacity of national and local governments.
The Africapolis database includes census data, satellite imagery and other cartographic sources to generate data that is internationally comparable. The Africapolis definition of an urban agglomeration is a continuous built-up area with less than 200 metres between buildings and a minimum of 10,000 inhabitants. Accordingly, small towns with up to 100,000 inhabitants in sub-Saharan Africa account for 90% of all urban centres.
Beyond density and size – the making of a small town
The DEGURBA and Africapolis definitions provide useful indications of how many people live in densely-settled areas, and of their needs for basic infrastructure and services. They do not, however, account for the complex dynamics of economic and social change that underpin urbanisation.
A more detailed definition of ‘urban’ that includes urban functions such as the provision of services, facilities and infrastructure, the economic structure and the employment sectors of residents is likely to more closely reflect the reality.
It would also provide more useful information for local governments as it would help identify the diverse needs of residents, their vulnerabilities and the hazards they face. But for this to happen, local governments need adequate financial resources and technical capacity.
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