Using detailed historical data for the cities of Glasgow and Edinburgh, evidence is found in support of the hypothesis that overcrowding is a significant cause of infant mortality. We distinguish between voluntary overcrowding (due to budgetary choices of poorer families) and involuntary overcrowding (due to market failure in the provision of an adequate supply of appropriate housing. We found that Glasgow's infant mortality rate was significantly higher than Edinburgh, despite their close geographical proximity, and that a large part of the difference can be attributed to involuntary overcrowding prior to World War II. We argue that this was due to the distinctly different housing policies adopted by the two cities, with lessons for present day public authorities
