Costa Ricans live longer than Americans. A new study shows how much the income distribution in the U.S. endangers the health of its poorest citizens.

Income differentials have a greater influence on the health of the population in the U.S. than in Costa Rica. That is what is reported by William Dow of the University of Berkeley together with his colleague Luis Rosero-Bixby from the University of Costa Rica in the professional journal PNAS. The researchers calculate that the mortality rate in the U.S. would fall by around 25 percent if there were no income differentials. In Costa Rica, it would only be 9 percent.

The life expectancy in Costa Rica stands at 78.5 years — about one year above that of Americans. At the same time, per capita income as well as expenditures for the health care system in the U.S. are many times higher. Analysis of health care data from the years 1984 to 2011, however, shows that the poorest 25 percent of Americans have, for example, almost a three times higher risk of dying from lung cancer than the upper quarter of the income distribution.

In Costa Rica, the lung cancer risk for the poorest [citizens] is less than twice as great as that of the richest. The researchers attribute that primarily to differences in health care. Thus, public health care in the U.S. only applied to those aged 65 and above in the time frames studied. In Costa Rica, the national insurance system has long since reached almost all citizens.