Effect of marital status on death rates. Part 1: High accuracy exploration of the Farr–Bertillon effect

Abstract

The Farr–Bertillon law says that for all age-groups the death rate of married people is lower than the death rate of people who are not married (i.e. single, widowed or divorced). Although this law has been known for over 150 years, it has never been established with well-controlled accuracy (e.g. error bars). This even let some authors argue that it was a statistical artifact. It is true that the data must be selected with great care, especially for age groups of small size (e.g. widowers under 25).The observations reported in this paper were selected in the way experiments are designed in physics, that is to say with the objective of minimizing error bars. Data appropriate for mid-age groups may be unsuitable for young age groups and vice versa.The investigation led to the following results. (1) The FB effect is very similar for men and women, except that (at least in western countries) its amplitude is 20% higher for men. (2) There is a marked difference between single/divorced persons on the one hand, for whom the effect is largest around the age of 40, and widowed persons on the other hand, for whom the effect is largest around the age of 25. (3) When different causes of death are distinguished, the effect is largest for suicide and smallest for cancer. For heart disease and cerebrovascular accidents, the fact of being married divides the death rate by 2.2 compared to non-married persons. (4) For young widowers the death rates are up to 10 times higher than for married persons of same age. This extreme form of the FB effect will be referred to as the “young widower effect”. Chinese data are used to explore this effect more closely.A possible connection between the FB effect and Martin Raff’s “Stay alive” effect for the cells in an organism is discussed in the last section.