The Jamaica Life Expectancy Paradox and Hookworm Eradication

Despite stagnant economic and living conditions, early 20th-century colonial Jamaica experienced a remarkable increase in life expectancy — a phenomenon referred to as the Jamaica Paradox. One factor believed to be key in this transformation was the Hookworm Campaign (1919-1936), an island-wide, multi-faceted public health initiative to eradicate hookworm, a tropical parasite that can severely weaken the immune system. Using parish-level mortality data and an event study framework, we investigate whether the campaign reduced mortality rates in Jamaica. Results show that infant deaths declined by 10% in the first year, cumulating to 41% within ten years. Mortality among other age groups also fell, although with several years of delay and lower effects. Our estimates suggest that by WWII the hookworm eradication effort increased life expectancy at birth by 5-15 years. A `back of the envelope' cost-benefit analysis reveals that the benefits in terms of spared infant deaths alone were multiple times the campaign costs, where the local population shouldered much of the overall costs.