Missing: 107 Million Atheists!

The 2015 results of the Gallup International poll for the demographics of atheism are out. I have been quoting for a while now the figure of 13% for the 2012 poll results but we now have a figure of 11% from the 2015 poll results. And that does give some food for thought.

Studies on the demographics of atheism have concluded that self-identified atheists comprise anywhere from 2% to 8% of the world's population, whereas irreligious individuals represent a further 10% to 20%. Several comprehensive global polls on the subject have been conducted by Gallup International: their 2012 poll found that 13% of respondents were "convinced atheists" and their 2015 poll indicated that 11% were "convinced atheists".
https://en.wikipedia.org/wiki/Demographics_of_atheism

It does show a worldwide drop in the percentage of atheism. Actually approximately 15% [2/13 x 100%]. But was there a drop in the actual population? The world population has grown through these years and perhaps the growth for atheists has outstripped their percentage drop? Let's find out.

The poll results have come out in the middle of the year so will assume the same for 2012. For 2012 the approximate world population size was 7 Billion. We will assume that for the middle of the year. It's pretty approximate and will do. The 2015 poll results have just come out and the current world population is approximately 7.3 Billion for the middle of 2015.
http://countrymeters.info/en/World

For 2012 we then approximate the population of atheists as 13% x 7 Billion = 910 Million

Similarly for 2015 we calculate 11% x 7.3 Billion giving 803 Million.

The difference is 910M - 803M = 107 Million Atheists.

So the world population growth has not outstripped the percentage drop for atheists and we actually have 107 Million of them missing!

And it does sort of leave you with the question, just where did they go?

It is actually possible to make an educated guess of this and we proceed as follows.

Note before proceeding that all my calculated values are basically a guess using approximations, except for any quoted figures such as the poll percentages and world population values etc.

And I am going to use previous quoted percentages and these will give reasonable approximate values. But they are just that, approximations.

Firstly, we need to work with an actual figure for the number living, so will have to remove the number who may have died.

A table of Historical and Predicted Crude Death Rates gives 8.3 for the years 2010-2015.
These are given as annual deaths per 1000 persons.
https://en.wikipedia.org/wiki/Mortality_rate#Statistics

So we need to approximate the total number of atheist deaths for the years 2012 to 2015 [middle of].
So thats 2012-2013,2013-2014, and 2014-2015. 3 years. Population growth approx 7 to 7.3 billion people.
3 years--let's just take an average. It will do. And we have 7.15 billion.

How many thousands of people?
7,150,000,000 / 1,000 = 7,150,000 or 7.15 million.

Probably wasn't hard to guess that one.

Then for the 3 years we can guess the approximate total number of people who have died as:

years x annual deaths per 1000 persons x number of 1000 persons =

3 x 8.3 x 7.15 million = approx 178 million.

And how many of these were atheists?

Again using the figures of 13% for 2012 and 11% for 2015 let's take the average: 12%.

Then we have 178 million x 12% = approx 21.4 million.

So of the 107 million atheists who are missing approximately 21.4 million of them have died.

That leaves 85.6 million.

So how do we redistribute this number into a population that makes sense? Simply by looking at some figures for religious populations. There are some figures available but trying to make sense of it all is not that easy. There is not complete agreement on the area of atheists.

The world factbook gives non-religious and atheist as 9.66% and 2.01%, together 11.67%
https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html

whereas Adherents.com gives 16% on a pie chart and 15.35% on a table for Secular/Nonreligious/Agnostic/Atheist. Well they state for the pie chart the figures are rounded up [giving a total higher than 100%] so that makes sense of the 15.35% value. So how do we make sense of the Gallup International poll results for 2012 and 2015 of 13% and 11% for those saying they were "convinced atheists"??
http://www.adherents.com/Religions_By_Adherents.html
https://en.wikipedia.org/wiki/Demographics_of_atheism
https://en.wikipedia.org/wiki/List_of_religious_populations

The pie chart 16% for "Nonreligious" states

inc. agnostic, theist, secular humanist, +people answering 'none' or no relig. preference. Half of this group is "theistic" but nonrelig.
http://www.adherents.com/Religions_By_Adherents.html

It's probably not too hard to have a guess at this. And it is just a guess but it is quite possible that some or a lot of the non-theist, non-agnostic part of this group when answering surveys select "atheist" whether they are fully atheist or not, simply because they are not agnostic or theist. It is quite possible for this reason the polls have returned values of 13% and 11% for the years 2012 and 2015 when other studies on the demographics of atheism have returned values as low as 2%.
https://en.wikipedia.org/wiki/Demographics_of_atheism

Note that the pie chart comment "Half of this group is 'theistic'" suggests that the actual atheistic part could be approximately 8% leaving the non-religious theistic part as also approximately 8%. And that value sits reasonably well with the Factbook quote of 9.66%.
https://en.wikipedia.org/wiki/Demographics_of_atheism

So allowing the theistic part of the non-religious group to be approximately 8% we can construct an approximate population spread. The Adherents.com spread is not too dissimilar to all the others so will use it with the theistic part of the non-religious group approximation of 8% and reconstruct the population to 100% using these values minus the atheists. We then have:

30.70 Christianity
22.32 Islam
13.95 Hindu
 5.25 Buddhist
 0.32 Sikh
 0.20 Jewish
 0.10 Baha'i
11.85 Other religions
 8.00 non-religious [our adjusted theistic part]
92.65 total
https://en.wikipedia.org/wiki/List_of_religious_populations#Adherent_estimates
as at 2015 July 12
Note: I have lumped everything else on their list into "Other religions" except the atheists, of course.

And the total of 92.65 here without atheists is not 100% so we now reconstruct the remainder to 100% giving:

     Christianity     33.13
     Islam            24.09
     Hindu            15.06
     Buddhist          5.67
     Sikh              0.34
     Jewish            0.22
     Baha'i            0.11
     Other religions  12.75
     non-religious     8.63 [our adjusted theistic part]
     Total           100.00

And finally from this last table we can construct an approximate table of where the missing 107 Million Atheists may have gone to:

     Missing: 107 Million Atheists
     Where did they go?
     ******************************
     Christianity             28.4M
     Islam                    20.6M
     Hindu                    12.9M
     Buddhist                  4.8M
     Sikh                      0.3M
     Jewish                    0.2M
     Baha'i                    0.1M
     Other religions          10.9M
     non-religious theistic    7.4M 
     died                     21.4M
     ******************************
     Total                     107M 

Of course this is all a guess. It's possible that the whole 107 Million Atheists became Catholics. It's possible, but very unlikely. More than likely the distribution spread could possibly be as we have suggested above.

And we close this study with a very well-known quote:

Page design/construction Stephen Buckley 2015.