The membership statistics provided in this book must be treated with great caution since many eastern churches exist in areas where no census regarding religious affiliation has been taken, or where the true size of church membership could have political implications. In each case I have consulted a number of sources and made my own judgment concerning an approximate membership figure. There were two sources I consulted most frequently. The first is the Second Edition of The World Christian Encyclopedia, D. Barrett, G. Kurian and T. Johnson, eds., Oxford University Press, 2001. The second is the series of International Religious Freedom Reports that were released by the Bureau of Democracy, Human Rights and Labor of the State Department of the United States in September 2006 (http://www.state.gov/g/drl/rls/irf/2006/). Each of these country reports contains a section on religious demography based on information the local US Embassy was able to gather about the size of each religious community. For the most part the membership figures in this book report the number of persons who self-identify as a member of a particular church, a number that is much higher than those who regularly participate in liturgical services.
In the case of the Eastern Catholic churches, I have taken figures exclusively from the 2007 Annuario Pontificio, the annual yearbook of the Vatican. It provides official membership statistics for every Catholic jurisdiction. I have added up the membership figures of all the jurisdictions of each Eastern Catholic Church and rounded off the sum to the next highest thousand. It should be kept in mind that these figures will be lower than the real membership of churches that have a significant presence in areas outside their land of origin. This is because the statistics do not include faithful of those churches that, lacking sufficient numbers to have an ecclesial structure, come under the jurisdiction of the local Latin bishops.
Given the large amount of information that is now available on the internet, this edition also includes the addresses of official web sites maintained by the various churches. I have not included web sites of local jurisdictions, but these can often be found as links on the pages of the mother churches. A useful list of official Orthodox web site and e-mail addresses can be found on the site of the Orthodox Church of America at http://www.oca.org.
In a departure from earlier editions of this book, three appendices to this seventh edition include brief descriptions of the ecumenical dialogues that the Catholic Church has with the Orthodox Church, the Oriental Orthodox Churches and the Assyrian Church of the East. Because of their importance as official texts of the churches involved, I thought it would be useful also to include the Common Declarations that have been signed by the heads of the churches in recent decades.
Any constructive comments that readers may wish to make on this text are welcomed, as well as updated information that could be considered for inclusion in subsequent editions of this book. Letters can be addressed to the author at St. Pauls College, 3015 Fourth Street NE, Washington, DC 20017 USA.