The future of religious denominations in the United States to 2043

Anne Goujon, Vienna Institute of Demography and International Institute for Applied Systems Analysis (IIASA)

We project the religious composition of the US, considering fertility differences, migration, intergenerational religious transmission and conversion by 11 ethnoreligious groups. If fertility and migration trends continue, Hispanic Catholics will experience rapid growth and expand from 10 to 18 percent from 2003 to 2043. Protestants could decrease from 47 to 39 percent over the same period, which means that Catholicism may be the largest religion among younger age groups. Particularly liberal Protestants loose ground due to low fertility and losses through conversion. Migration drives growth among Hindus and Muslims, while low fertility causes decline among the Jews. The low fertility of secular Americans and the religiosity of the immigrants provide a countervailing force for secularization, and the secular population share is expected to plateau before 2043.