Despite many limitations of the records showing cause of death and some degree of inaccuracy in the level of cause-specific mortality, the historical data indicate that infectious diseases predominated in the mid-18th century when overall mortality began to decline in England and other parts of Europe. Wrigley and Schofield's analysis of aggregated data from several hundred parishes in England confirmed the findings of earlier studies that mortality in England declined from the mid-18th century. All of the 11 severe mortality crises (30% above trend) occurred before 1750, and the last secondary crisis (20–30% above trend) was in 1762–63. After 1802–3 there were only two years in which mortality was more than 10% above the trend level, in 1846–47 and 1848–49. Figure 4.1 shows the dramatic change in the pattern of annual fluctuations in the crude death rate from the 1740s, and the greatly diminished spikes in annual mortality compared with earlier years. The death rate had generally been lower than the birthrate between 1540 and 1640, and population may have approached the limit that could be fed given the land available and the state of agricultural technology. Although there does not appear to have been an increase in subsistence crises, the increase in demand would have led to increased food prices, exacerbating poverty. From the 1740s, the more rapid population growth put further pressure on food supplies, which had to be increased just to maintain existing levels of average consumption per capita.

Wrigley and Schofield found that short-term variations in mortality were determined by factors other than food supply and there was little correlation between food supply and mortality over the long run. Using their aggregate data, Fogel found that less than 10% of “crisis mortality” (50–100% above normal) in England between 1541 and 1871 was due to famines, and that the decline in mortality was not due primarily to a reduction in “crisis mortality,” whether caused by famines or not.