Death rates for U.S. infants, children, teenagers and young adults are falling, particularly among those in poor regions, likely due to social policies that have helped the most disadvantaged families, researchers said on Thursday. Their study, using county-level U.S. Census Bureau data from 1990 to 2010, found that even with persistent economic inequality among Americans, the gaps in death rates and life expectancy between rich and poor young people have narrowed.

"The health of the next generation in the poorest areas of the United States has improved tremendously," University of Zurich economist Hannes Schwandt said. "Previous research has largely focused on diverging trends among older Americans, ignoring these improvements."

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"We are surprised about the remarkable mortality reductions among infants, children and young adults, and about how little a role this great health success story has played in academic and public discussions," Schwandt added.

For example, deaths in the first three years of life for boys in the wealthiest counties dropped by 4.2 per 1,000 births to a rate of 5.53 per 1,000 births between 1990 and 2010. These deaths declined during that time span by 8.49 per 1,000 births to 9.79 per 1,000 births in the poorest counties. Figures for girls were similar. For males ages 15-19, the probability they would die within three years declined by 0.73 per 1,000 to 1.92 per 1,000 in the wealthiest counties from 1990 to 2010. In the poorest counties, there was a decrease in this group of 2.73 per 1,000 to 3.10 per 1,000.

"It's the kind of good news that is hard to sell, opposing the popular narrative that 'Everything is getting worse,'" Schwandt said. 

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Princeton University economist Janet Currie said the United States has invested in the "safety net" for poor children in recent decades. She noted the expansion of the Medicaid program and the creation of the State Child Health Insurance Program to widen healthcare coverage for poorer young people as well as growth in publicly funded preschool programs and the expansion and improvement of child nutrition programs such as food stamps and subsidized school lunches.

"These programs are paying off in terms of lower mortality and better health for children. Since there is a great deal of evidence that healthier children grow up to be healthier adults,these trends auger well for the future of these cohorts (populations)," Currie said. The research was published in the journal Science.