Religious Distance

Differences in religion amongst countries are measured using three scales:

R1 is a 5 point scale which quantifies the difference between the dominant religions of any two countries, i and j,

R2 is a 5 point scale based on the incidence of country i’s dominant religion(s) in country j, and

R3 is a 5 point scale based on the incidence of country j‘s dominant religion(s) in country i.

The scores for each of these indicators and the resultant factor (see below concerning the confirmatory factor analysis) can be found in the attached Excel spreadsheet. This spreadsheet contains the values for 14,280 country pairs (i.e. n x n-1 for 120 countries). The precise coding for these variables is explained below. 


Time Period:

The religion population data represent forecasts for the year 2000; however, these forecasts were based on trend data from the 1980s.  While this represents quite an old data set, population trends in religious affiliation (like language) are very slow to change (i.e. they are primarily generational changes), and our scales are intentionally coarse grained; thus our indicators of differences in religion should not be adversely affected.


R1  – Distance Between Major Religions

The distance between the two closest major religions for each pair of countries is based on that classification system and is coded as follows:  

5 – Different families of religion
4 – Same family but different religions
3 – Same religion but different division
2 – Same division but different denomination or sect
1 – Same denomination or sect


R2 & R3 – Incidence of One Country’s Major Religion(s) in Other Countries

The second and third religion indicators measure the proportion of the population in one country that belong to the same religion as a significant proportion of another country. 

R2 concerns the incidence of country i’s major religion(s) in country j, and
R3 concerns the incidence of country j’s major religion(s) in country i.  The indicators are coded as follows:  

5 – Less than 1%
4 – Greater than or equal to 1% but less than 5%
3 – Greater than or equal to 5% but less than 50%
2 – Greater than or equal to 50% but less than 90%
1 – Greater than or equal to 90%  

Where a country has more than one major religion, a weighted average is calculated.  



A major religion is defined as any religion to which more than 20% of the population claim an affiliation. 

Within a religion which is deemed ‘major’, only the divisions which represent at least one quarter of that religion’s adherents are deemed relevant for this analysis.  E.g. Sunni Muslims must represent at least 25% of a county’s Muslims to be considered a ‘major’ group. 

Similarly, only denominations and sects which represent at least one quarter of that religion’s division are considered ‘major’.  E.g. Baptists must represent at least 25% of a country’s Protestants to be considered in the analyses. 

If no divisions or denominations/sects reach that threshold, the largest division and denomination/sect will be used.   

For the 120 countries used in these analyses, 8 religions, 11 corresponding divisions/rites, and 28 denominations/sects qualified as ‘major’. 

These religions have been grouped into a hierarchy of families of religions, religions, divisions of within each religions (e.g. denominations/sects). 

These categories are based on a range of sources:

Barrett, D. B., World Christian Encyclopedia, 1982;  
Whaling, F., Religion in Today’s World, 1987
Harris, I. et al, Contemporary Religions: A World Guide, 1992;
O’Brien, J. & M. Palmer, The State of Religion Atlas, 1993;
Glasse, C., The Concise Encyclopedia of Islam, 2001; and .

Two Excel files documenting the hierarchy of religions and the major religions for each country are attached at the bottom of this page.


Relig– Differences in Religion Factor:

The preceding three indicators have be reduced to a single factor using confirmatory factor analysis (cfa).  This factor score has been estimated using all 14,280 country pairs.  The individual factor loadings and the Cronbach alpha are reported below.

  Religf – 3 item factor score for differences in religion    0.8434
  R1 – Distance between Major Religions 0.826
  R2 – Incidence of i’s major religion in country j 0.899
  R3 – Incidence of j’s major religion in country i 0.893



The primary sources for these estimates were:

    • Barrett, D. B., World Christian Encyclopedia, 1982
    • CIA Factbook, 2002
    • (Jewish Agency for Israel), accessed 23 February 2006