Mormon Attrition 1975-2014

At the Mormon church’s April General Conference, church leader Quentin Cook remarked the following on the number of members leaving the church:

“Some have asserted that more members are leaving the Church today and that there is more doubt and unbelief than in the past. This is simply not true. The Church of Jesus Christ of Latter-day Saints has never been stronger. The number of members removing their names from the records of the Church has always been very small and is significantly less in recent years than in the past.”

Even though the Mormon church doesn’t actually report the number of members leaving the church, it’s still easy to prove apostle Cook wrong with simple arithmatic and an appeal to common sense. First the arithmatic:

Members this year = members last year + children + converts – members lost

Solving for members lost yields:

Members lost = members last year – members this year + children + converts


Members lost in 2013 = members 2013 – members 2014 + children 2014 + converts 2014

= 15,082,028 – 15,372,337 + 116,409 + 296,803

= 122,903

Doing this for every year since 1975 (when the church started reporting numbers of children and converts) yields the following chart:

In some years, the attrition is negative, which could mean people rising from the dead and rejoining the Mormon church, or reinforcements being beamed in from Kolob. These years have been reset to zero in this chart (pending confirmation of 250,000+ resurrections). 

The red line on this chart shows that the number of members lost since 1975 is in an upward trend from about 35,000 to 75,000 per year on average. It is not known how many of these are deaths or resignations so this is where common sense kicks in. There are four possibilities:

1. Deaths and resignations are both increasing;
2. Deaths or resignations are increasing while the other remains constant;
3. Deaths are increasing more than resignations are decreasing;
4. Resignations are increasing more than deaths are decreasing.

According to the United Nations, death rates around the world have decreased by about 20% between 1975 and 2015. This decrease is less dramatic in the US, where most Mormons live, but still a decrease of about 8%. In South America, where most Mormons outside the US live, the mortality decrease is even 30%.

That leaves only option 4: resignations are increasing at a rate that not only offsets the 8-30% mortality decrease in Mormonism’s primary markets but actually doubles the rate at which members are lost.

The situation is the same if we look at lost members as a percentage of total members over the last 25 years, as apostle Cook suggests in the footnote to his statement:

Here, too, the attrition rate is in an upward trend. It is safe to say, then, that unless Mormons die younger than their non-Mormon peers, it is unlikely that “the number of members removing their names from the records of the Church is significantly less in recent years than in the past”.