World Christian Database

Why "Quarterly" Updates

Quarterly updates are not only opportunities to introduce completely new features or fields or modules to the Database, as is often the case, but every update inherently includes the results of a further three months of research.

Changes are made almost daily to the underlying master database from the scores of sources that become available every day. But it is every three months that all these changes are freshly reconciled with each other to create the comprehensive and internally consistent picture published quarterly in the World Christian Database.

With 7 billion people growing and changing and moving every day, the population of each People group relative to others, the percentage of each religion in each People and hence in each country, the size of each denomination, and of each city and province, is constantly, and often subtly, changing.

Every day new information becomes available as to which of those subtle shifts have bubbled to the surface to become apparent and noticeable. Every day forecasts and estimates of one statistic or another are refined by researchers across the world.

The change in one statistic invariably effects others. If a denomination has turned out to be growing twice as fast as expected, it is not enough to just change that one statistic--depending on where the growth came from, other denominations or other religions will have declined, and the religious percentages of the People groups effected will also change accordingly.

A change in today's statistic may also effect estimates of past years, and will of course effect future projections.

Sometimes whole sets of underlying data change at once, and an example of this is the publication of the 17th edition of the Ethnologue which provides a new set of language statistics with newly discovered languages, some languages becoming extinct or merging with others, some split into two or more languages. Each new or changed piece of language information may result in religious composition changes which ripple through the present year to past and future years.

Sets of data like the Ethnologue, or new country censuses or surveys can take many days or weeks to analyze and process into a coherent picture. (Preliminary results from the new Ethnologue data should be available in October).

Each quarter the picture will change because each day things are changing, but the quarterly updates should always be internally consistent and based on the latest reliable globally reconciled data.