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

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 great accuracy. This even let some authors argue that it was a statistical artefact. It is true that the data must be selected and analyzed with great care, especially for age groups of small size such as widowers under 25. The observations reported in this paper were selected and designed in the same way as experiments in physics, that is to say with the objective of minimizing the error bars for all age-groups. It will be seen that 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 basically the same for men and women, except that on average it is about 20\% stronger for men. (2) There is a marked difference between single or divorced persons on the one hand, for whom the effect is largest around the age of 45, 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. (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." A possible connection between the FB effect and Martin Raff's "Stay alive" effect for cells in an organism is discussed in the last section.Comment: 30 pages, 17 figure

Effect of marital status on death rates. Part 2: Transient mortality spikes

We examine what happens in a population when it experiences an abrupt change in surrounding conditions. Several cases of such "abrupt transitions" for both physical and living social systems are analyzed from which it can be seen that all share a common pattern. First, a steep rising death rate followed by a much slower relaxation process during which the death rate decreases as a power law (with an exponent close to 0.7). This leads us to propose a general principle which can be summarized as follows: "ANY abrupt change in living conditions generates a mortality spike which acts as a kind of selection process." This we term the Transient Shock conjecture. It provides a qualitative model which leads to testable predictions. For example, marriage certainly brings about a major change in environmental and social conditions and according to our conjecture one would expect a mortality spike in the months following marriage. At first sight this may seem an unlikely proposition but we demonstrate (by three different methods) that even here the existence of mortality spikes is supported by solid empirical evidence.Comment: 42 pages, 18 figure

The detection of cheating in multiple choice examinations

Cheating in examinations is acknowledged by an increasing number of organizations to be widespread. We examine two different approaches to assess their effectiveness at detecting anomalous results, suggestive of collusion, using data taken from a number of multiple-choice examinations organized by the UK Radio Communication Foundation. Analysis of student pair overlaps of correct answers is shown to give results consistent with more orthodox statistical correlations for which confidence limits as opposed to the less familiar "Bonferroni method" can be used. A simulation approach is also developed which confirms the interpretation of the empirical approach.Comment: 16 pages, 13 figure

Deciphering the fluctuations of high frequency birth rates

Here the term "high frequency" refers to daily, weekly or monthly birth data. The fluctuations of daily birth numbers show a succession of spikes and dips which, at least at first sight, looks almost as random as white noise. However in recent times several studies were published, including by the present authors, which have given better insight into how birth is affected by exogenous factors. One of them concerns the way adverse conditions (e.g. famines, diseases, earthquakes, heat waves) temporarily affect the conception capacity of populations, thus producing birth rate troughs 9 months after mortality waves. In addition, religious interdicts (e.g. during the Lent period) lead to reduced conceptions. These as well as other effects raise the hope that we will soon be able to "read" and interpret birth rate patterns just as the Egyptologist Jean-Francois Champollion managed to decipher many (though not all) hieroglyphs.Comment: 23 pages, 10 figure

The physics of large-scale food crises

Investigating the ``physics'' of food crises consists in identifying features which are common to all large-scale food crises. One element which stands out is the fact that during a food crisis there is not only a surge in deaths but also a correlative temporary decline in conceptions and subsequent births. As a matter of fact, birth reduction may even start several months before the death surge and can therefore serve as an early warning signal of an impending crisis. This scenario is studied in three cases of large-scale food crises. Finland (1868), India (1867--1907), China (1960--1961). It turns out that between the regional amplitudes of death spikes and birth troughs there is a power law relationship. This confirms what was already observed for the epidemic of 1918 in the United States (Richmond et al. 2018b). In a second part of the paper we explain how this relationship can be used for the investigation of mass-mortality episodes in cases where direct death data are either uncertain or nonexistent.Comment: 29 pages, 11 figure