Even with likely over-reporting of Thai numbers, Buddhism has a surprisingly small influence by percentage.
- “Buddhists made up roughly 7% of the world’s population in 2015, but they are expected to decrease to roughly 5% by 2060. This is because Buddhists have relatively low fertility rates compared with other religious groups, and they are not expected to grow significantly due to conversions or religious switching.”
(Compared to 31% Christian and 24% Muslim, notably Muslims are expected to grow to 31% by 2060)
- “Half the world’s Buddhists live in China, according to 2010 Pew Research Center estimates. Still, they make up only 18% of the country’s population. Most of the rest of the world’s Buddhists live in East and South Asia, including 13% in Thailand (where 93% of the population is Buddhist) and 9% in Japan (35% Buddhist). Only about 1.4% of the world’s Buddhists live in countries outside of Asia.”
I’m doubtful that the Thai population is truly 93% Buddhist. It seems this number comes from 2010 census data where only registered religions are an option, i.e. ignoring unregistered groups such as atheists.
- “Buddhists make up roughly 1% of the adult population in the United States.”