Smoking cessation has been a major driver of mortality improvement in the past
decades. Upon quitting, extra mortality risk gradually falls over 20 years and
eventually fades away.
Developed countries had substantial
success in curbing smoking, but the rate
of quitting has slowed down. In the United States, smoking prevalence remained
relatively stable in the 1990s, although it
dropped further afterward. The U.K. also
had much slower cessation rates in recent
years, compared to the 1970s and 1980s.
As smoking cessation slows down,
it gradually becomes a less powerful
mortality improvement driver. Smoking
cessation, like obesity, has a long-term
impact rather than creating a short term
There are many other smaller drivers of mortality such as climate change
and antimicrobial resistance. There is
also a worrying trend of rising mortality
among middle-aged white Americans.[ 5]
Although these could have a material impact on population mortality, they tend
to have an impact over the longer term.
As a result, they are not adequate to explain the sudden mortality increase.
With these drivers not quite fitting
with the 2015 mortality increase, other
event-based possibilities were considered. One that stood out was the recovery
from the Great Recession, which is event-based and has a systematic impact. We
discovered that historically, mortality
experienced a brief increase in the few
years following a major recession. To
understand this better, let’s first look at
the mortality after the Great Depression.
Mortality After the Great
The Great Depression remains the lon-
gest and the most severe depression
experienced in industrialized Western
history. In 1927, there was a mild eco-
nomic recession in the United States
followed by a stock market crash in Oc-
tober 1929. Panic in the financial world
quickly spread through the entire econ-
omy. When the Great Depression
reached its nadir in 1933, 13 million to 15
million Americans were unemployed.
Impacts spread to Canada and Europe.
Contrary to the intuition that mortal-
ity would increase during a depression,
population mortality did not see an up-
tick during the Great Depression. A
report by the League of Nations showed
no appreciable effect on the aggregate
mortality rates of the countries included
in the study, which included the United
States, the U.K., Germany, Italy, and a
few others.[ 6] This can also be seen from
historical life expectancy in Figure 2.
Despite the uneven pattern prior to the
Great Depression in 1929, life expectancy
increased afterward (green box). In 1929,
there was a decrease in life expectancy,
especially in the U.K., but it was mostly
attributed to an influenza epidemic in
that year. An exception to this was suicide
mortality, which increased significantly.
Surprisingly, mortality experienced
FIGURE 1. Increased deaths from major causes as a percentage
of total increased deaths, comparing 2015 to 2014 .
Source: CDC; ONS