Two people can live in the same city yet face dramatically different chances of reaching old age. In Buenos Aires, the neighborhood itself was tied to a gap in life expectancy of nearly fifteen years for men. Life expectancy in small areas of cities is relatively common to study in high-income countries but rare in Latin American countries.

This study examined how life expectancy was distributed across small areas of Buenos Aires and how it was associated with neighborhood socioeconomic characteristics. The study used death records, population information, and neighborhood socioeconomic information to estimate life expectancy at birth.

The city was divided into geostatistical small areas, each based on an average of about five thousand households, as defined by Argentina’s national statistics institute. The study linked georeferenced death records from twenty fifteen to twenty seventeen to the city’s three hundred fifty-one small areas.

The study also used population information and socioeconomic data from the two thousand ten census to characterize conditions in those small areas. The pattern was geographic: life expectancy was higher in the north and northeast of the city than in the south and southwest.

A higher-life-expectancy strip also ran through the center, surrounded by areas with lower life expectancy. The map therefore revealed a pattern across place, not just a citywide average. In Buenos Aires, expected lifespan depends strongly on where people live: it is generally longer in the north and northeast, while the south and southwest fare worse, with a separate higher-lifespan strip through the center.

This uneven pattern makes neighborhood conditions impossible to ignore. Women had higher life expectancy than men across the city, and that pattern also held when life expectancy was considered at ages twenty, forty, and sixty.

But the bigger surprise was the spread between neighborhoods: the difference between the highest and lowest areas was 9.3 years for women and 14.9 years for men. Education, school attendance, and access to water were linked with higher life expectancy, while unemployment and overcrowding were linked with lower life expectancy.

All of these neighborhood conditions were associated with life expectancy, and the relationships were stronger among men. For education, men in areas with the highest levels had 5.63 more years of life expectancy than men in areas with the lowest levels. The estimates used all registered deaths during the study period and were linked to small areas.

The study could also inform research that includes the wider metropolitan area around Buenos Aires. There was an important limitation: neighborhood conditions came from the two thousand ten census, while deaths came from twenty fifteen to twenty seventeen, so the time difference could bias the results.

Life expectancy was not evenly distributed across Buenos Aires: better education, school attendance, water access, and less unemployment and overcrowding went together with longer lives. Health policy therefore has to improve places, not only individuals.