Changes

==Convergence in late 20th century==

==Convergence in late 20th century==

[[Image:Longevity disparities.JPG|thumb|400px|{{A-image|U.S. Department of Health and Services; Data from U.S. Department of Health and Human Services, synthesized by Singh GK, Siahpush M. (2006) [http://dx.doi.org/10.1093/ije/dyl083 Widening socioeconomic inequalities in US life expectancy,  1980–2000. (Free Full-Text)] Int. J. Epidemiol. Advance Access Publication; Chart from data in Singh and Siahpush’s report by the New York Times, March 23, 2008.<br/>|}}Widening socioeconomic inequalities in life expectancy among Americans during 1980 to 2000.]]

[[Image:Longevity disparities.JPG|thumb|400px|{{A-image|U.S. Department of Health and Services; Data from U.S. Department of Health and Human Services, synthesized by Singh GK, Siahpush M. (2006) [https://dx.doi.org/10.1093/ije/dyl083 Widening socioeconomic inequalities in US life expectancy,  1980–2000. (Free Full-Text)] Int. J. Epidemiol. Advance Access Publication; Chart from data in Singh and Siahpush’s report by the New York Times, March 23, 2008.<br/>|}}Widening socioeconomic inequalities in life expectancy among Americans during 1980 to 2000.]]

Becker et al. (2005) use estimates of gains in life expectancy along with per capita income statistics for a more valid analysis of cross-country welfare equality. Between 1960 and 2000, the mortality rate fell in many countries due to technological improvements in health care. Poorer countries utilized the technology and knowledge previously available in more wealthy nations to reduce the mortality rate of young people by providing more effective medical intervention to those afflicted with infectious, respiratory, or digestive diseases. Econometric analysis of income per capita from Penn World Tables and life expectancy data from the World Bank indicates that inequality of welfare between countries has been reduced.

Becker et al. (2005) use estimates of gains in life expectancy along with per capita income statistics for a more valid analysis of cross-country welfare equality. Between 1960 and 2000, the mortality rate fell in many countries due to technological improvements in health care. Poorer countries utilized the technology and knowledge previously available in more wealthy nations to reduce the mortality rate of young people by providing more effective medical intervention to those afflicted with infectious, respiratory, or digestive diseases. Econometric analysis of income per capita from Penn World Tables and life expectancy data from the World Bank indicates that inequality of welfare between countries has been reduced.

To explain these changes, demographers have used longitudinal studies. They support the proposition that the extent and severity of chronic conditions in middle and late life are to a large extent the outcome of environmental insults at early ages, including in utero. Data from the Early Indicators Project, undertaken at the Center for Population Economics at the University of Chicago, suggest that the range of differences in exposure to disease narrowed greatly over the course of the 20th century, that age-specific prevalence rates of chronic diseases were much lower at the end of the 20th century than they were at the beginning of the 20th century or during the last half of the 19th century, and that there was a significant delay in the onset of chronic diseases over the course of the 20th century. These trends appear to be related to changes in levels of environmental hazards and in body size. These findings have led investigators to posit a synergism between technological and physiological improvements. This synergism contributed to reductions in inequality in real income, body size, and life expectancy during the 20th century.<ref>Fogel (2005)</ref>

To explain these changes, demographers have used longitudinal studies. They support the proposition that the extent and severity of chronic conditions in middle and late life are to a large extent the outcome of environmental insults at early ages, including in utero. Data from the Early Indicators Project, undertaken at the Center for Population Economics at the University of Chicago, suggest that the range of differences in exposure to disease narrowed greatly over the course of the 20th century, that age-specific prevalence rates of chronic diseases were much lower at the end of the 20th century than they were at the beginning of the 20th century or during the last half of the 19th century, and that there was a significant delay in the onset of chronic diseases over the course of the 20th century. These trends appear to be related to changes in levels of environmental hazards and in body size. These findings have led investigators to posit a synergism between technological and physiological improvements. This synergism contributed to reductions in inequality in real income, body size, and life expectancy during the 20th century.<ref>Fogel (2005)</ref>

Yet, in respect of the United States, life expectancy appears to be widening between socioeconomic groups. In 2006 epidemiologists Gopal K. Singh and Siahpush<ref name=singh2006>Singh GK, Siahpush M. (2006) [http://dx.doi.org/10.1093/ije/dyl083 Widening socioeconomic inequalities in US life expectancy,  1980–2000. (Free Full-Text)] Int. J. Epidemiol. Advance Access Publication.

Yet, in respect of the United States, life expectancy appears to be widening between socioeconomic groups. In 2006 epidemiologists Gopal K. Singh and Siahpush<ref name=singh2006>Singh GK, Siahpush M. (2006) [https://dx.doi.org/10.1093/ije/dyl083 Widening socioeconomic inequalities in US life expectancy,  1980–2000. (Free Full-Text)] Int. J. Epidemiol. Advance Access Publication.

*'''<u>Abstract:</u>'''

*'''<u>Abstract:</u>'''

:*'''Background:''' This study examines changes in the extent of inequalities in life expectancy at birth and other ages in the United States between 1980 and 2000 by gender and socioeconomic deprivation levels.  

:*'''Background:''' This study examines changes in the extent of inequalities in life expectancy at birth and other ages in the United States between 1980 and 2000 by gender and socioeconomic deprivation levels.