Ever since the establishment of economic history as an independent discipline, the causes of the Industrial Revolution have been its Holy Grail. The reason for this quest is not hard to find, for the Industrial Revolution marks the onset of an epochal change in the material well-being of humanity, the era of modern economic growth. In northwestern Europe, where the Industrial Revolution first occurred, the improvement in the level of living of the average person over the past two centuries has been tenfold or more, representing a rate of advance unprecedented in human history.

In demographic history, however, a quite different revolution has been the focus of attention, that in human life expectancy. Since 1870, life expectancy at birth in many areas of the world has soared from values around 40 years or less to 70 years or more. The reduction in mortality has been accompanied by an associated improvement in health as the incidence of contagious disease has dramatically lessened. This lengthening of life and associated reduction in morbidity brought about by the “Mortality Revolution” has meant at least as much for human welfare as the improvement in living levels due to modern economic growth. Certainly the Mortality Revolution has substantially affected a much wider segment of the world's population.

Surprisingly, the Mortality Revolution has gone largely unremarked in the discipline of economic history.