More than half the world now lives in urban areas. In many low- and middle-income countries, the speed and scale of urban growth has outpaced the provision of services, leading to a proliferation of informal settlements without access to water and sanitation, garbage collection, or security of tenure. The urbanization and concentration of poverty and deprivation in these settings is often characterized by residential crowding, exposure to environmental hazards, and social fragmentation and exclusion (Wratten, 1995) – a cluster of conditions frequently referred to with the catch-all term of “slum-dwelling.”
Policy and media discussions about urban poverty tend to focus on slums, the characterization of which is presumed to be straightforward. But there are many different ways in which slums can be defined, ranging from the United Nation’s “universal” definition” – insufficient living area, non-durable housing, lack of access to improved water, lack of access to improved sanitation facilities, and security of tenure – to more local-, state-, and city-level characterizations.
Community-level deprivation has important implications for human health and wellbeing. Concentrated open defecation, crowding, and exposure to environmental pollutants have all been associated with infectious disease transmission and risk of mental health issues (Subbaraman et al., 2014), among other poor outcomes related to human health and wellbeing. But there has been very little research into the ways in which areas and communities are identified as slums, and how this may affect the association between slum dwelling and health.
In an article published in the March issue of Population and Development Review (Nolan, 2015), I examine various ways of defining slum dwelling, and explore how choice of definition affects the relationship between slum-dwelling and child health (proxied by children’s height and weight for age). This type of research is important for promoting the thoughtful measurement of important concepts and variables used in the research-to-policy pipeline, and for producing nuanced and thoughtful program and policy recommendations based on this information.
I use National Family and Health Survey (NFHS) data from 2004-2005 (International Institute for Population Sciences and Macro International, 2007) from eight cities in India (Chennai, Delhi, Hyderabad, Indore, Kolkata, Meerut, Mumbai, and Nagpur) because of: 1) the very large size and growth of the urban population in India, 2) the accessibility of data in which multiple definitions of slum dwelling may be compared, and 3) the policy relevance of the topic. Given that the Indian government has developed policy initiatives such as the Rajiv Awas Yojana, which envisages a “slum-free India” (Ministry of Urban Housing and Poverty Alleviation. 2010), it may benefit from empirical work on the implications of the measurement of the urban poor population.
In the paper described above, I compare four different definitions of slum dwelling (please see the published article for more detail on their empirical construction):
- The 2001 “Census” definition is a country-wide administrative characterization based on registration of the area and other characteristics.
- The “NFHS” definition is based on survey enumerator supervisor observations of slum characteristics.
- The “UN” definition is comprised of universally recognized components of a healthy environment (UN-HABITAT, 2006/7).
- The “Committee” definition has been tailored to the Indian context as recommended for the 2011 Census in a Report to the Committee on Slum Statistics/Census (Ministry of Housing and Urban Poverty Alleviation, 2008).
I find that the percent of children in the study sample identified as living in slums in each city varies widely by definition. In the capital city of New Delhi, the UN definition indicates that 65 percent of children live in slums, whereas the Committee definition identifies only 32 percent of children as living in slums. The Venn diagram below shows the overlap between different slum designations, providing additional support for the variability in overlap between definitions. This should give pause to researchers, policymakers, and public health practitioners who might consider slum-dwelling to be conceptually or empirically straightforward.
I also find that only children characterized by the UN definition as living in slums have poorer health than non-slum dwellers (controlling for available confounding variables). More specifically, these slum-dwelling children have a height that is on average 11 percent of a standard deviation lower than their non-slum-dwelling counterparts; they also weigh significantly less. This relationship between slum dwelling and poor health is most strongly driven by high-density living. These findings demonstrate that the manner in which a slum is defined appears to determine which families are defined as slum-dwellers, and whether a relationship is found between slum-dwelling and child health.
There are a number of potential explanations for the relatively small overlap among the four slum designations. First, the Census was conducted in 2001, while the NFHS was undertaken in 2005-2006. Thus, it is possible that slum areas changed substantially between these dates (Montana et al., 2014) an issue that is infrequently addressed when assessing area-level deprivation. A second reason may be the variation in components that make up the four definitions. While the Census includes notification (i.e. recognition as a legal settlement by a governing body), the other definitions consist of a variety of characteristics associated with slum-dwelling, with one definition based on enumerator observation alone, and the two others differing significantly in terms of the number of slum-related indicators the households – and by extension the communities in which they are located – must exhibit.
Administrative distinctions such as notification are particularly important in the Indian context, where legal status confers rights to the provision of public services. A definition that depends solely on government recognition may underestimate the prevalence of communities with slum characteristics (Agarwal, 2011), and likely overlook some communities experiencing the highest levels of exclusion and disadvantage (Subbaraman et al., 2012), while definitions that include notification along with other area characteristics may be more inclusive. These findings underscore the importance of the measurement of public policy problems for promoting transparency and greater nuance in the way in which poverty is studied empirically and addressed in policy.
Agarwal S. 2011. The state of urban health in India; comparing the poorest quartile to the rest of the urban population in selected states and cities. Environment and Urbanization. 23:13–28.
International Institute for Population Sciences and Macro International. 2007. National Family and Health Survey (NFHS-3) 2005–2006: India. Mumbai: IIPS.
Ministry of Housing and Urban Poverty Alleviation. 2008. Report of the Committee on Slum Statistics/Census. New Delhi, India: Government of India, Ministry of Housing and Urban Poverty Alleviation.
Ministry of Urban Housing and Poverty Alleviation. 2010. Rajiv Awas Yojana: Guidelines for Slum-Free City Planning. New Delhi: Government of India.
Montana L, Lance PM, Mankoff C, Speizer IS, Guilkey D. 2014. Using satellite data to delineate slum and non-slum sample domains for an urban population survey in Uttar Pradesh, India. Spatial Demography. 2(2).
Nolan LB. 2015. Slum Definitions in Urban India: Implications for the measurement of health inequalities. Population and Development Review. 41(1): 59–84.
Subbaraman R, O’Brien J, Shitole T, Shitole S, Sawant K, Bloom DE, Patil-Deshmuck A. 2012. Off the map: The health and social implications of being a non-notified slum in India. Environment and Urbanization. 24:643–663.
Subbaraman R, Nolan LB, Shitole T, Sawant K, Shitole S, Sood K, Nanarkar M, Ghannam J, Betancourt TS, Bloom DE, Patil-Deshmukh A. 2014. The psychological toll of slum living in Mumbai, India: A mixed methods study. Social Science and Medicine. 119:155–169.
UN-HABITAT. 2006/7. State of the World’s Cities 2006/2007. Nairobi, Kenya
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