Buddhism’s Shrinking Numbers Worldwide: Aging Population & Religious Switching

Buddhists are the only major religious group globally whose numbers have declined between 2010 and 2020, falling from 343 million to 324 million – a roughly 5% decrease, according to a recent Pew Research Center analysis of religious demographics in 201 countries and territories.

This decline in Buddhist populations occurs even as the global population grew by 12% during the same period, and other major religious groups experienced growth. Buddhists now represent 4.1% of the world’s population, down from 4.9% in 2010.

The reasons behind this shrinking population are complex, but center on two key demographic trends: an aging Buddhist population with relatively low birth rates, and a significant number of individuals raised Buddhist who no longer identify with the faith as adults – a process known as religious switching.

The Demographic Challenge: Aging and Low Fertility

Buddhists, as a group, are older than adherents of other major world religions. The median age of Buddhists worldwide was approximately 40 in 2020, nine years older than the global population median of 31. This represents also older than the median ages of Jews (38), Christians (31), Hindus (29), and Muslims (24).

This aging population is coupled with low fertility rates. Buddhist women, on average, have 1.6 children, significantly lower than the global average and below the replacement rate of 2.1 children per woman needed to maintain population size. This low fertility rate contributes to a shrinking base of potential future Buddhists.

The impact of these demographic factors is particularly pronounced in East Asia – China, Japan, South Korea, Taiwan, and Hong Kong – where the population is aging rapidly and birth rates are low. These five countries account for roughly 40% of the global Buddhist population, and experienced a 22% decline in Buddhist numbers between 2010 and 2020.

Religious Switching: Leaving the Faith

While Buddhism attracts converts, the number of people leaving the faith outweighs those joining it. For every 100 adults raised Buddhist, 12 have converted to Buddhism, but 22 have left, resulting in a net loss of 10 adherents per 100 people raised Buddhist. This pattern of religious switching is a significant driver of the overall decline.

This trend is especially visible in Japan, where roughly half of adults raised Buddhist no longer identify with the religion, and in South Korea, where six in ten have switched away from Buddhism. However, this pattern isn’t universal. In Thailand, a Southeast Asian country with the largest Buddhist population globally, the vast majority of those raised Buddhist continue to identify with the faith.

Geographic Concentration and Regional Variations

The vast majority – 98% – of Buddhists live in the Asia-Pacific region. This geographic concentration means that demographic trends within this region have a disproportionate impact on global Buddhist numbers. While East Asia has seen a decline, other parts of the Asia-Pacific region have experienced slower growth, and the rest of the world has seen more substantial increases.

The combined population growth in China, Japan, South Korea, Taiwan, and Hong Kong was only 5% between 2010 and 2020, compared to 13% in the rest of the Asia-Pacific region and 16% globally. This slower growth in East Asia contributes significantly to the overall decline in Buddhist numbers.

What Does This Mean for the Future?

The Pew Research Center analysis suggests that the decline in the global Buddhist population is likely to continue if current demographic trends persist. The combination of an aging population, low fertility rates, and religious switching creates a challenging environment for the growth of Buddhism.

However, it’s important to note that these trends are not uniform across all regions. The situation in Southeast Asia, particularly in countries like Thailand, is different, and the future of Buddhism in these regions may be more stable. The continued attraction of converts to Buddhism also offers a potential offset to the losses from religious switching, though currently, it is not enough to reverse the overall decline.

Related: 5 facts about Buddhists in the United States