1、The Health Penalty of Chinas Rapid Rapid urbanization could have positive and negative health effects, such that the net impact on population health is not obvious. It is, however, highly pertinent to the human welfare consequences of development. This paper uses community and individual level longi
2、tudinal data from the China Health and Nutrition Survey to estimate the net health impact of Chinas unprecedented urbanization. We construct an index of urban city from a broad set of community characteristics and define urbanization in terms of movements across the distribution of this index. We us
3、e difference-in-differences estimators to identify the treatment effect of urbanization on the self-assessed health of individuals. The results reveal important, and robust, negative causal effects of urbanization on health. Urbanization increases the probability of reporting fair or poor health by
4、5 to 15 percentage points, with a greater degree of urbanization having larger health effects. While people in more urbanized areas are, on average, in better health than their rural counterparts, the process of urbanization is damaging to health. Our measure of self-assessed health is highly correl
5、ated with subsequent mortality and the causal harmful effect of urbanization on health is confirmed using more objective (but also more specific) health indicators, such as physical impairments, disease symptoms and hypertension. Urbanization and economic development are intimately related (Williams
6、on, 1988). There is no better example of this than China in recent decades, where a remarkable rate of economic growth has been accompanied by a process of urbanization that is unprecedented in human history, both in scale and in speed. The proportion of the Chinese population living in urban areas
7、increased from only 20% in 1980, to 27% in 1990, and reached 43% in 2005 (NBS, 2006； World Bank 2006). By the middle of this century, the countrys urbanization rate has been forecast to reach 75% (Yusuf and Saich, 2008). In the space of just a few decades, China will complete the urbanization proces
8、s that lasted hundreds of years in the West. The non-economic consequences of such rapid urbanization, including those for health, as well as more obviously for the environment, will determine the true welfare effects of development and the extent to which it is sustainable. The consequences for pop
9、ulation health are not obvious. On the one hand, urban living offers improved access to modern medicine (particularly in China) and gains in income that can be invested in health. On the other, the health of city dwellers is threatened by air pollution, more sedentary and possibly more stressful wor
10、k, social detachment, and Western, high-fat diets. This paper uses panel data from China covering the period 1991-2004 to estimate the net health impact of urbanization. On average, health outcomes are found to be better in urban parts of the developing world (Van de Poel et al, 2007； Zimmer et al,
11、2007). This apparent urban health advantage contrasts with the historical evidence of urban populations suffering poorer health in Western Europe prior to and during its period of industrialization (Rosen, 1958； Woods, 1985, 2003). The most likely explanation for this difference in the urban-rural h
12、ealth disparity over time and space is the marked decline in the prevalence of infectious diseases, in low-income as well as high-income countries (Riley, 2005), prompted, in large part, by public health measures built on the germ theory of disease (Preston, 1975, 1980； Cutler and Miller, 2005) and
13、the introduction of effective medicines, antibiotics and vaccinations (Davis, 1956； Cutler et al, 2006； Soars, 2007). In the past, the opportunities for material gain offered by cities had to be weighed against the dangers of infection. Today, while cities of the developing world continue to pose ri
14、sks to health, the immediate threat to life through infection has receded. However, the overcrowding and pollution that accompany urbanization, particularly on the scale and speed with which it has occurred in China, may impose an urban health penalty. During the last decades, Chinas environment has
15、 deteriorated significantly as rapid urbanization and industrialization generate enormous volumes of air and water pollutants (World Bank, 1997； Wang and Smith, 2000； Brajer and, 2003).1 As other developing countries, most notably India, China relies very heavily on coal as a source of energy, with
16、the result that levels of airborne pollution in Chinese cities are many times greater than those found in most US and European cities (Pandey et al, 2006).2 A World Health Organization study has estimated that there are 300,000 premature deaths per year in Chinese cities attributable to outdoor air
17、pollution (Cohen et al, 2004).3 Urbanization brings social and economic changes that can raise risk factors associated with chronic disease. Urban populations of middle-income countries are experiencing a rapid nutritional transition towards Western-style diets, dominated by more processed foods and
18、 a high fat content (Popkin, 2001； Popkin and Du, 2003). Urbanization inevitably implies a shift in work patterns from physical, agricultural labor towards more sedentary occupations (Monda et al, 2007). In China, it is claimed that these transitions have contributed to stark increases in the preval
19、ence of obesity and hypertension (Liu et al, 2004；Wang, Mi et al, 2007； Weng et al, 2007). But urbanization clearly has positive, as well as negative, consequences for population health. Closer proximity to health care facilities, particularly hospitals, equipped with modern technology and staffed b
20、y highly trained doctors is an obvious advantage of living in towns and cities. In China, urban-rural differences in access to health care, and in health insurance cover, have been marked and widening in recent decades (Liu et al, 1999). Access to schools and to health education initiatives confer a
21、 strong advantage on urban areas in the field of preventative health care. Urban populations can also use higher incomes to invest in health through health care, a nutritious diet or by reducing strenuous work effort(Moore et al, 2003).In this paper, we estimate the net effect of urbanization on hea
22、lth using longitudinal data from the China Health and Nutrition Survey (CHNS). Besides being a household panel, this survey also collects data on the characteristics of communities, making it possible to identify what happens to individuals health when the environment in which they live becomes more
23、 urbanized. This identification strategy avoids the selection biases that arise from comparisons between the health of urban and rural populations, or from monitoring the health of migrants, which is difficult or impossible in any case with most panel data. A dichotomous urban-rural classification,
24、most often done on the basis of population density, does not capture the variation in living and health conditions across areas at different stages of urbanization (McDade and Adair, 2001； Vlahov and Galea, 2002； Champion and Hugo, 2004； Dahly and Adair, 2007). In addition, there is a practical problem in that the categorization of an area as urban or rural is often fixed over waves of a longitudinal survey, as it is in the CHNS, and so this categorization does not
