By Anne Goujon, Research Scholar, IIASA World Population Program
Today, Catholics are one of the fastest-growing religious affiliations in North America, because of migration and higher fertility levels—for example, the fertility of Catholic women in the USA is 12% higher than that of the Protestants. Could Catholics become the largest religious group in North America?
In a new book chapter that I wrote with Éric Caron Malenfant and Vegard Skirbekk, we projected the future religious landscape of the USA and Canada, based on a range of scenarios with different combinations of hypotheses regarding future changes of fertility, conversion and secularization rates, and migration.
Based on our projections, the answer is no, North America would not be relative majority Catholic by the middle of the century. But by 2062, it would be a near-tie for the largest religious group in the country: our projections of the religious composition of Canada and the U.S. reveal that for most scenarios, Catholics would make up to 32% of the population, compared to 34% for Protestants.
What drives changes in religious affiliation in a population? Our projections show that the key forces are migration and religious mobility, rather than fertility levels. In fact, most of the change in the relative share of the Catholics and Protestants in North America would be due to the decline in the share of the Protestant population – especially in the USA – rather than by the increase of the share of the Catholic population, which remains quite stable. Our range of scenarios stresses that the religious switch is driven by demographic factors such as migration and the policies that affect these factors. For example, if migration to the USA from Mexico were to decrease, there would be a lower share of Catholics in North America by 2060.
In 2062, our projections show that religious diversity will increase, with growing shares of Islam, Hinduism and Buddhism, and other religions. This religious diversification would be more pronounced in Canada than in the U.S. In Canada, our projections show the share of other religions would triple according to most scenarios until the 2060s, from around 10% to around 30%, while the same share would increase from 6% to 15% in the U.S. in almost all scenarios. Unless there is a rapid shift in conversion, migration, or fertility levels, our projections show a growth in minority religions, driven mostly by continued immigration, a younger age structure, higher fertility, and low losses through secularization and conversion to other religions.
What about people who leave the religion of their family, moving from a religious affiliation to no affiliation? In both countries, more than one in five adults today has a different religion than he/she had in childhood or that of his/her parents. However, in all our scenarios, the population with no religion stays more or less constant up to 2062 at around 17%. This is explained by low shares of non-affiliated persons among immigrants to the U.S. as well as low childbearing levels among non-affiliated people in both Canada and the USA.
Why do changes in the religious landscape matter? Changes in a country’s religious heterogeneity that follow demographic change may affect nations’ culture, value orientations, and policies. The religious composition of a society may also have demographic effects, including behavior and family formation decisions. North America has already witnessed significant changes to its religious make-up in recent years.
Anne Goujon, Éric Caron Malenfant, Vegard Skirbekk. 2015. “Towards a Catholic North America?” The Changing World Religion Map, pp 1689-1709. http://link.springer.com/chapter/10.1007%2F978-94-017-9376-6_89#
Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.