This book utilises the first-difference panel regression analysis to assess the direct effect of urban slum prevalence or the proportion of the total population living in urban slum conditions on national level measures of infant mortality rates over the period 1990 to 2005. Utilising data on 81 less developed countries, the results illustrate increasing urban slum prevalence over the period is a robust predictor of increasing infant mortality rates. This effect obtains net the statistically significant influence of gross domestic product per capita, fertility rate, and female secondary school enrolment. The results confirm urban slum prevalence growth is an important contextual dynamic whereby the social production of infant mortality is enacted in the less developed countries.