This story was recently taken up by the Guardian Express and International Business Times who responded to a prediction from my book Why Atheism will Replace Religion. Unfortunately these writers made mistakes. I want to correct some of those errors and clarify the actual claim.

First the correction

The Las Vegas Guardian Express writer, Rebecca Savastio falsely attributes to me the claim that religion “will completely disappear by 2041.” What I do project is that religious people will comprise a minority by that date, a very different prediction.

Writing for the International Business Times, Conor Adams Sheets editorializes that “it is quite a leap in logic to suggest that rising financial security will lead inexorably to a rejection of religion.” His rationale, apparently, is that some “thought leaders” have expressed a different opinion.

Yet, the data on this issue could not be clearer. Given what we now know about the predictive relationship between economic development and rising secularism, it is perversely illogical to argue that “religious beliefs will enjoy a resurgence as the world continues to develop.” Numerous empirical studies point in exactly the opposite direction.

Given the strength of the data, the claim that religious belief will increase with economic development is as much of a logical stretch as claiming that although short people weigh less than tall people today, they will magically weigh more in the near future. Tall people are clearly heavier on average and developed countries are clearly more secular today. The same correlations will hold up in the future. So let’s wake up to the facts.

Now the clarification

Research has shown that religion declines not just with rising national wealth but also with all plausible measures of the quality of life, including length of life, decline of infectious diseases, , the rise of the welfare state, and more equal distribution of income.

Clearly, there is less of a market for religion in societies where ordinary people feel secure in their daily lives. In the most developed countries, such as Japan and Sweden, the quality of life is so good that the majority is already secular.

In my book, I asked how long it would take for the average country in the world to reach a similar level of development as countries that already have secular majorities. This transition was measured either as a minority believing in God, or a minority seeing religion as important

The average rate of economic development was assessed both in terms of GDP (corrected for local prices, PPP) and the Human Development Index (HDI) that includes health and education as well as GDP.

So I calculated four estimates of when the average country in the world is likely to transition to a secular majority and the average estimate was 2041. The more reliable HDI method predicts an earlier transition than GDP alone.

All such extrapolation is notoriously risky, of course and all bets would be off if the world fell into a 20-year as it currently shows no sign of doing, already recovering to trend growth levels following the 2009 downturn. Ditto for a major asteroid collision, or a catastrophic failure of earth’s ecosystem.

The argument that religious people will out reproduce their secular neighbors is intriguing but ultimately flawed because development reduces fertility for everyone as illustrated by contemporary American Mormons and by Ireland that is newly secular and newly wealthy.

Will religion ever disappear?

I never claimed that religion would disappear by 2041 but only that it would lose its present majority clout. Currently about three quarters of the world’s inhabitants are religious in the sense of seeing religion as important in their lives.

My estimate implies a less than 1 percent decline per year to the 50 percent transition to minority status. At a similar pace of decline, it would take three times longer for religion to fall below 1 percent, i.e., a decline of 75 percent rather than 25 percent.

I have no way of knowing whether religion can decline to that extent. On the other hand, I am on much firmer ground in predicting that the global population will switch over to majority secularism because there are several countries from Japan to Sweden where that has already happened.