Eastern Orthodoxy by country
The number of members of the Eastern Orthodox Church in each country has been subject to a lot of debate. Each study performed that seeks to discover the number of adherents in a country may use different criteria, and be submitted to different populations. As such, some numbers may be inflated, and therefore inaccurate. Examples of this are Greece and Russia, where estimates of adherence to Eastern Orthodoxy may reach 80-98%, but where surveys found lower percentages professing Eastern Orthodoxy or belief in God. The likely reason for this disparity is that many people in these majority Eastern Orthodox countries will culturally identify with the Eastern Orthodox Church, especially if they were baptized as children, even if they are not currently practicing. This includes those who may be irreligious, yet culturally identify with the Eastern Orthodox Church, or for whom Eastern Orthodox Christianity is listed on official state records. Other cases of incongruent data also might be due to counting ethnic groups from Eastern Orthodox countries rather than actual adherents. A case of this is the United States, which has large numbers of immigrants from Eastern Orthodox countries. The Eastern Orthodox jurisdictions often reported large numbers of members, which together would total 2-3 million across the country. However, a 2010 study by Alexei Krindatch sought data from each parish, with the specific criteria of annual participation. This study produced the "Atlas of American Orthodox Christian Churches", and discovered that there were only about 817,000 Eastern Orthodox Christians actively practicing their faith (that is to say, attending church services on a regular basis) in the United States. The study explained that such a difference was due to a variety of circumstances, for example the higher numbers having counted all people who self-identify as Eastern Orthodox on a census regardless of active participation, or all people belonging to ethnic groups originating in Eastern Orthodox countries. This study, while initially controversial, proved groundbreaking, and has since been officially approved for use by the Assembly of Canonical Orthodox Bishops of the United States of America.
Coptic Orthodox Church of Alexandria
There are about 20 million Coptic Orthodox Christians in the world. Between 15 and 18 million of them are found in Egypt under the jurisdiction of the Coptic Orthodox Church of Alexandria. Since Egypt does not have an official government census on religion, estimates of the size of Egypt's Christian population vary from the estimated low previous government figures of 6 to 7 million to the 12 million reported by some Christian leaders in 2008. The actual numbers may be in the 15 to 18 million range, out of an Egyptian population of more than 90 million. However, in 2011, the Pew Research Center announced that Copts in Egypt constitute 4.5% of the population, while the Catholic Holy See puts Copts at 6 to 8%. Then in 2017 government owned news Al Ahram estimated the percentage of Copts at 10 to 15%. However, in 2012 after the Egyptian revolution the Muslim Brotherhood was drafting new constitution then Major-General Abu Bakr al-Guindi claimed that the lower figures support a downward trend in the percentage of Copts in Egypt, as recorded in consecutive estimated Egyptian censuses since a 1927 high where Egyptian Christians formed 8.3% of the population. This decline has been explained by Major-General Abu Bakr al-Guindi, head of Egypt's Central Agency for Public Mobilization and Statistics, as being the result of Copts having the highest emigration rate, the lowest birthrate and the highest income level in the country. Although many Copts rejected this statement and population count by Abu Barker al-Guindi claiming they have been undercounted as most Copts reside in Upper Egypt.