Preface to the Annual Series
This annual yearbook series emerges from several projects on international religious demography that have developed over the past several decades. First, in 1982, Anglican researcher David B. Barrett published a comprehensive, global assessment of religious affiliation with the award-winning World Christian Encyclopedia (Oxford University Press). Barrett studied the demographics of Christianity in detail but also collected data on other religions. Thus, Barrett produced the first country-by-country comprehensive statistical assessment of religion. Todd Johnson joined Barrett in 1989 and helped him to produce the second edition of the World Christian Encyclopedia (2001). In 2003, Johnson moved the research center to Gordon-Conwell Theological Seminary near Boston, where he established the Center for the Study of Global Christianity and launched the World Christian Database (Brill, 2007)—an online database with detailed demographics on over 9,000 Christian denominations. In 2009, he co-edited the Atlas of Global Christianity (Edinburgh University Press) with Kenneth R. Ross, offering a visual representation of religious demographics.
Second, the Pew Research Center in Washington, dc has given significant priority to researching international religious demography. Through the work of sociologist Brian Grim—and, more recently, Conrad Hackett, Phillip Conner, and other demographers and sociologists—Pew has released a series of reports on various aspects of religious demography (available at www.pewforum.org).
In 2008, Todd Johnson and Brian Grim started the International Religious Demography Project at Boston University’s Institute on Culture, Religion and World Affairs (cura). This project has provided space for working out the methodology of religious demography and further strengthening of the collaboration between the Center for the Study of Global Christianity and other research centers. The World Religion Database (Brill), the source of most of the data in parts 1 and 2, was launched in 2008. As one of our first research projects, Gina Zurlo, now with a Ph.D. from Boston University worked on best estimates for Jewish populations in every country. The World Religion Database is updated every quarter, and new variables are added regularly.
Third, Vegard Skirbekk, now a professor at Columbia University and Senior Researcher at the Norwegian Institute of Public Health, also joined the project and provided detailed analyses of demographic characteristics of religions. In particular, Skirbekk studies how religion and religiosity impacts fertility levels, which can influence both demographic growth and whether a particular set of cultural values will be passed to younger generations.
Fourth, in 2013, The World’s Religions in Figures: An Introduction to International Religious Demography by Todd M. Johnson and Brian J. Grim (Wiley-Blackwell) was published as an introduction to the academic discipline of counting religionists around the world. It examines methods and techniques in the context of national, regional, and global statistics on religious adherents. This yearbook intends to continue and extend that conversation.
The increased prominence religion has assumed in academic fields including history, sociology, international relations, and a host of others is one of the unexpected developments of the early twenty-first century. In the latter part of the twentieth century, conventional wisdom held that religion was on the wane and, by implication, that the study of religion was of little importance to understanding the world. In particular, leading anthropologists and sociologists such as Anthony F.C. Wallace and Bryan Wilson predicted the demise or even disappearance of religion within a very short time. One of the first sociologists to recant this position was Peter Berger, who founded the Institute on Culture, Religion and World Affairs (cura) at Boston University and later published The Desecularization of the World (Eerdmans, 1999). Other books, such as John Micklethwait and Adrian Wooldridge’s God is Back (The Penguin Press, 2009), show that journalists’ and scholars’ treatments of religion as a passing fad were not simply minor oversights. God’s Century: Resurgent Religion and Global Politics (W.W. Norton, 2011) by Monica Duffy Toft, Daniel Philpott, and Timothy Samuel Shah offers evidence that a lack of attention to religion has greatly hindered international relations and peacemaking efforts. In 2014, Peter Berger once again revised his decades-long understanding of secularization theory in The Many Altars of Modernity: Toward a Paradigm for Religion in a Pluralist Age (De Gruyter Mouton).
In the meantime, the number of sources of religious data has greatly expanded (see Part 3 for an overview of major sources). Approximately half of the world’s national censuses ask questions on religion. Religious communities continue to collect data on their members and publish annual reports of the results. Professional survey groups conduct polls and surveys, increasingly outside of the Western world. Scholars are writing monographs on religious communities, including their demographics. All of these data offer a rich repository of information for an assessment of religious demographics.
While the main purpose of this yearbook is to describe in detail how one counts religionists around the world, we felt that it would be helpful to provide a summary of the number of people counted in each religion in the first two parts. While in other publications maps are used to display these data, in this volume the data are presented in sets of tables. Explanations of the methodology, sources, and analytical techniques behind these figures follow in the remainder of the book. The documentation for our estimates resides in various databases and research centers: The World Christian Database and World Religion Database, the Center for the Study of Global Christianity at Gordon-Conwell Theological Seminary (South Hamilton, ma), the Pew Research Center (Washington, dc), the Institute on Culture, Religion and World Affairs (Boston, ma), and the International Institute for Applied Systems Analysis (Vienna, Austria).
Brian J. Grim
Todd M. Johnson
Vegard Skirbekk
Gina A. Zurlo
Institute on Culture, Religion and World Affairs, Boston University
February 2018