© 2005 American Public Health Association DOI: 10.2105/AJPH.2004.056721
Kate E. Pickett is with the Department of Health Sciences, University of York, York, England. Jessica Mookherjee is with the Department of Anthropology, University College London, London, England. Richard G. Wilkinson is with the Division of Epidemiology and Public Health, University of Nottingham Medical School, Nottingham, England. Correspondence: Requests for reprints should be sent to Kate E. Pickett, PhD, Department of Health Sciences, University of York, Seebohm Rowntree BuildingRoom A/TB/220, Heslington, York YO10 5DD UK (e-mail: kp6{at}york.ac.uk).
Income inequality has been associated with both homicides and births to adolescents in the United States and with homicides internationally. We found that adolescent birth rates and general homicide rates were closely correlated with each other internationally (r= 0.95) and within the United States (r = 0.74) and with inequality internationally and within the United States. These results, coupled with no association with absolute income, suggested that violence and births to adolescents may reflect gender-differentiated responses to low social status and could be reduced by reducing income inequality.
Violence and births to adolescents seem to stand out as gender-differentiated markers of the corrosive effects of poverty among young people.13 Although adolescent births and levels of violence are strongly associated with poverty within developed countries, national rates of both violence and adolescent births are nevertheless higher in several wealthy countries compared with poor countries. In other words, homicides and adolescent pregnancies appear to be associated with relative rather than absolute poverty. Indeed, the degree of income distribution within a society has been linked to homicide rates within and outside the United States (see, for example, Hsieh and Pugh,4 Wilkinson et al.,5 Daly et al.,6 and Fajnzylber et al.7), but only within the United States for adolescent births.8,9 We decided to investigate how much these 2 social problems were related to each other and, if they have common roots, whether these roots might lie in relative or in absolute deprivation.
International Comparisons Countries were included if they were among the 50 countries with the highest gross national income per capita by purchasing power parity in 2002, had populations of more than 3 million, and had data on income inequality. The eligible countries were Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Greece, Ireland, Israel, Italy, Japan, The Netherlands, New Zealand, Norway, Portugal, Singapore, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and the United States. Data on income inequality came from the United Nations Development Program Human Development Indicators; dates for each country vary slightly from country to country but are within the period 19921998.10 Income inequality was measured as the ratio of the total annual income received by the richest 20% of the population to the total average annual income received by the poorest 20% of the population. Gross national income per capita by purchasing power parity was measured in US dollars and obtained from the World Bank World Development Indicators database.11 Data on births per 1000 women aged 15 to 19 years for 1998 came from UNICEF.12 Adolescent birth rates were unavailable for Israel, Singapore, and Slovenia, and these countries were excluded from our study. Data on homicides came from the United Nations Survey on Crime Trends and the Operations of Criminal Justice Systems.13 Homicide data were period averages of available rates per 100000 persons for 19902000.
US Comparisons
Statistical Methods
Figure 1
The effect of per capita income differed in the 2 comparisons. Internationally, higher per capita income was associated with higher rates of adolescent births and homicides (P < .001), whereas in the United States, higher per capita income was associated with lower adolescent birth rates (P < .001) and was not significantly related to homicide rates. The Pearson correlation coefficient for juvenile homicides and income inequality was 0.31 (P = .035), and for juvenile homicides and per capita income it was effectively zero (0.001; P = .994) (data not shown). The international associations between each outcome and income inequality were removed by controlling for the other. In the United States, an attenuated correlation remained between income inequality and adolescent births.
Our findings suggested that the links between deprivation and both violence and adolescent births reflect the destructive psychosocial and behavioral effects of inequality. As Luker19 put it, it is "the discouraged among the disadvantaged" who become adolescent mothers. Gilligan20 and others pointed out how often violence among young men is triggered by humiliation and disrespect. Successful programs for preventing adolescent pregnancy and violence have often focused on personal development, attempting to undo the psychosocial costs of low social status.1,21 But these patterns demand a common explanation. Our study suggests that levels of relative deprivation may be an underlying cause. Interestingly, the decline in US homicide and adolescent birth rates since the 1990s was accompanied by declining unemployment and improved relative income among the poorest individuals.17,22
Peer Reviewed
Contributors
Human Participant Protection Accepted for publication January 22, 2005.
1. Health Development Agency. Teenage Pregnancy and Parenthood: A Review of Reviews. London, England: Health Development Agency, National Health Service; 2003. Evidence Briefing. 2. The Alan Guttmacher Institute. Teen Sex and Pregnancy: Facts in Brief. New York, NY: The Alan Guttmacher Institute; 1999. 3. Wilson M, Daly M. Competitiveness, risk-taking and violence: the young male syndrome. Ethol Sociobiol.1985;6:5973. 4. Hsieh C-C, Pugh MD. Poverty, income inequality, and violent crime: a meta-analysis of recent aggregate data studies. Crim Justice Rev.1993;18:182202. 5. Wilkinson RG, Kawachi I, Kennedy BP. Mortality, the social environment, crime and violence. Sociol Health Illn.1998;20:578597.[CrossRef] 6. Daly M, Wilson M, Vasdev S. Income inequality and homicide rates in Canada and the United States. Can J Criminol.2001;43:219236. 7. Fajnzylber P, Lederman D, Loayza N. Inequality and violent crime. J Law Econ.2002;45:140. 8. Gold R, Kawachi I, Kennedy BP, Lynch JW, Connell FA. Ecological analysis of teen birth rates: association with community income and income inequality. Matern Child Health J.2001;5:161167.[Medline] 9. Gold R, Kennedy B, Connell F, Kawachi I. Teen births, income inequality, and social capital: developing an understanding of the causal pathway. Health Place.2002;8(2):7783.[CrossRef][Web of Science][Medline] 10. United Nations Development Program. Human Development Report. New York, NY: Oxford University Press; 2003. 11. World Development Indicators [database online]. Washington, DC: World Bank; 2004. Available at: http://www.worldbank.org/data/wdi2004. Accessed December, 2004. 12. A League Table of Teenage Births in Rich Nations: Innocenti Report Card. Florence, Italy: UNICEF Innocenti Research Centre; 2001. Report No. 3. 13. United Nations Crime and Justice Information Network. Survey on Crime Trends and the Operations of Criminal Justice Systems (Fifth, Sixth, Seventh). New York, NY: United Nations; 2000. 14. Table S4: Gini ratios by state: 1969, 1979, 1989, 1999. Washington, DC: Income Statistics Branch/Housing and Household Economic Statistics Division, US Census Bureau; 2004. Available at: http://www.census.gov/hhes/income/histinc/state/state4.html. Accessed April 13, 2005. 15. Census 2000 Summary File 3. Washington, DC: US Census Bureau; 2003. 16. Ventura SJ, Mathews TJ, Hamilton BE. Teenage births in the United States: state trends, 19912000, an update. Natl Vital Stat Rep. May 30, 2002;50(9): 14.[Medline] 17. Crime in the United States. Washington, DC: Federal Bureau of Investigation; 19902000. 18. Office of Juvenile Justice and Delinquency Prevention. Juvenile Offenders and Victims: 1999 National Report. Pittsburgh, Pa: National Center for Juvenile Justice; 1999. 19. Luker K. Dubious Conception: The Politics of Teen-age Pregnancy. Cambridge, Mass: Harvard University Press; 1996. 20. Gilligan J. Violence: Our Deadly Epidemic and Its Causes. New York, NY: GP Putnam; 1996. 21. Center for the Study and Prevention of Violence. Blueprints Model Program Descriptions, FS-BP02. Boulder: University of Colorado; 2004. Available at: http://www.colorado.edu/cspv/blueprints/model/overview.html. Accessed April 13, 2005. 22. The Alan Guttmacher Institute. The Guttmacher Report on Public Policy. New York, NY: The Alan Guttmacher Institute; 1998. This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||