What Causes Religions to Grow

I read a nice summary of the history of the various faiths. It starts with a review of the three variables that drive growth of various religions, wars, births and persuasion.

While conquering large populations has served Christianity and Islam well it is no longer available. Birth numbers were big for both but are declining for both as well as for Buddhism. What remains available for all religions is persuasion. The religions with the most money can do the most marketing.

When numbers from Africa are thrown in, Christianity and Islam are both doing ok. Both of them have gone into those countries with their money and missionaries. Local religions that worship local gods have declined as their members have been persuaded to convert to the two big organization. In addition, birth rates have remained high in Africa adding to the numbers of Christians and Muslims already there.

When per-person incomes rise around the world something quite predictable happens. Women have access to education and begin working outside the home. When this happens, the cost of a child goes up. There is more money to raise a child but the income loss by a birth, which did not exist before, quickly enters the decision about child bearing. The birthrate falls.

If Africa experiences some economic growth we can expect a lower birthrate there and fewer children in both Christianity and Islam. This has not happened and may not.

All of this illustrates the role of economics and demography in religion. We have to conclude that the religions of the world would be different if events in the secular had taken a different turn.