Later, smaller, better? Water infrastructure and infant mortality in Finnish cities and towns, 1870–1938

We analyse the role of modern water infrastructure in reducing infant mortality in Finnish cities and towns in the late nineteenth and early twentieth centuries. Estimates from US data suggest that urban water infrastructures greatly affected the health transition in Western countries, implying policy lessons for developing countries. Finland is a relevant case due to the early onset of mortality decline in a predominantly agrarian context in a country with a low GDP. Our sources enable analysis across population centres of varying size as well as over different phases of development. We construct panel data on infant mortality and the initiation of three major water interventions – piped water, sewers and chlorination – in 37 Finnish cities and towns from approximately 1870 to 1938. We show that in line with previous literature, the interventions had a significant effect on infant mortality, jointly accounting for roughly 40% of the average decrease in different cities. However, most of the measurable effect was driven by small- and medium-sized cities adopting more advanced technology in the twentieth century rather than by pioneering larger cities in the nineteenth century. Weighting by population size rather than using average effects reduces the estimate to about 32%. Due to low levels of urbanisation, the measurable impact on national mortality decline was only about 4–5 % over the entire period, but roughly twice as high in the twentieth century, when both urbanisation and a decline in urban infant mortality rates gathered pace. Following development economics, our findings emphasise the importance of distinguishing the effects of sanitation by period and developmental context rather than compressing them into a single estimate.