Although mortality in Britain showed a long term decline from as early as the eighteenth century, it stagnated in the nineteenth century under the pressures of urbanisation and industrialisation. This paper examines the economic factors which lay behind the resumption of the mortality decline in Britain 1870–1914. A framework of analysis is developed which distinguishes factors in the physical environment (like population density) which affected mortality directly, from price and income movements which affected decisions about expenditure on sewers, water supplies, food, medical staff. A regression analysis of mortality in a sample of 36 towns in England and Wales suggests increases in the incomes of households and town council tax revenues were instrumental in the decline of mortality. This allowed extra spending not only on food, as McKeown emphasised, but also on a wide range of health-enhancing goods and services. The major improvement in the physical environment was the housing stock which rose faster than the population whilst its quality and dimensions were increasingly regulated by central and local government.