Sanitary infrastructures and the decline of mortality in Germany, 1877-1913

Clean water provision is considered crucial towards eradicating water-borne diseases. However, the benefits of piped water are limited in the absence of efficient systems of waste disposal due to recontamination or the exposure of citizens to excrement. In this article, I analyse the historical experience of German cities and estimate the impact of water supply and sewerage systems on mortality. The results show that waterworks lowered mortality, although to a lower extent than suggested previously. I observe a much stronger effect of sanitary interventions in cities that also established sewerage systems. Together they explain 19 percent of the overall mortality decline during this period. Three pieces of evidence show that the limited effects of waterworks is related to illnesses spread via faecal-oral transmission mechanisms. First, sanitary infrastructures account for a quarter of the decline in infant mortality, which is largely affected by water-borne ailments. Second, I find a large effect for enteric-related illnesses, while deaths from etiologies with a different pathological basis are not affected. Finally, the estimated effect is related exclusively to the sanitary interventions because mortality only declines significantly after their completion, and not before.