The population health and income nexus in the Mississippi River Delta Region and beyond.

The association between health and income has been well established using cross-country panel data. This paper explores this association further using data for corresponding cross sections of counties in the United States in 1970 and 2000. Special attention is paid to the stability of the associations over time and to differences between counties in the Mississippi River Delta Region and those in the rest of the United States. Regression results show that income is positively correlated with improvements in life expectancy over the period 1970 to 2000. This relationship strengthens from 1970 to 2000 for the U.S. and the non-Delta region and weakens slightly for the Delta region. Decomposition analysis shows that income explains more of the improvements in life expectancy from 1970 to 2000 for the Delta region (49%) than for the U.S. (35%) or the non-Delta region (32%). Factors other than income are less important in the Delta region during this time period. In 1970, income (64%) explains more of the difference in health between the Delta and non-Delta counties than non-income factors (36%). By the year 2000, non-income factors (77%) explain more of the disparities in health between the Delta and non-Delta countries than income factors (23%). For the year 2000, if the Delta region were to count on increased income to improve life expectancy to the average of the non-Delta region, it would need to increase its income level by 135%. The analysis indicates that population health in the Mississippi River Delta Region lags behind the rest of the United States not only because of lower income levels, but more importantly because of lower contributions to health of non-income factors.