Interpreting Average Annual Growth Rates (AAGRs)

Determining the Average Annual Growth Rates for a church or a group of churches in a region allows us to establish where the Church is growing, either in the number of believers or number of churches, and where it is not. In other words, the AAGRs establish the FACTS of Church growth; but the Church Growth Analyst also wants to understand the FACTORS causing this growth or decline. To determine the FACTORS, further investigation is needed. This article will identify general Church Growth FACTORS so that the researchers can further investigate their contribution to growth in specific situations.

1. Factors to take into consideration when interpreting AAGRs

    1.1. Studying the Growth Factors in a Single Congregation.
    1.2 Studying Growth Factors in a Region
    1.3 Matters for Caution

2. Factors Contributing to the Growth of the Number of Churches

1. Factors to take into consideration when interpreting AAGRs

Those who study Church Growth point out that that numerous factors contribute to growth. Sometimes growth factors are categorized as Natural/Biological Growth and Conversion Growth.

  • Biological growth describes those who are born to Christian parents coming to personal faith.
  • Conversion growth describes those who are born of non-Christian parents coming to personal faith.

A thoughtful person will correctly point out that “coming to personal faith” in both Biological Growth and Conversion Growth indicates spiritual conversion. Point well taken. However these terms are used in a technical sense to assist the analysis of growth factors and will be used as defined.

Both Natural/Biological Growth and Conversion Growth are net measures of several positive and negative factors.

Biological or Natural Growth is a net measure of at least four dynamics: Births and Deaths, Immigration and Emigration. These are the same measures that contribute to the Average Annual Population Growth.

Conversion Growth also has at least two components: the number of those accepting the Christian Faith from non-Christian Backgrounds and those from Christian backgrounds who reject the faith delivered to their forefathers.

Biological Growth is a good measure of how well the Church is discipling the next generation birth within the faith community. Conversion growth is a measure of how well the Church is discipling those outside the faith community.

1.1. Studying the Growth Factors in a Single Congregation.

When studying the growth of a single congregation, it is possible to take a closer look at the FACTORS that contribute to the AAGR. From Church records (if good records have been kept), it is possible to discover:

  • The number of births per year (a positive factor)
  • The number of deaths per year (a negative factor)
  • The number of members who have moved away or transferred church membership (negative)
  • The number of new members who have transferred Church membership (positive)
  • The number of baptisms (positive)
  • The number of baptisms of people coming from Non-Christian Families (sub category of baptisms)
  • The number of baptisms of people coming from Christian Families (sub category of baptisms)
  • Number of excommunications/people who have renounced their faith (negative)

Here we have collected more FACTS to help us understand what has happened. It is also useful to to interview leaders and church members to understand other contributing factors, for example, a change in leadership, an outpouring of the Holy Spirit, beginning a second worship service, establishing growth goals, beginning a new outreach, etc. Or on a negative note, division of a church, moral failure of a church leader, a major employer in the area closed that contributed to a loss of jobs and people moving away, etc. By examining the contributing factors to the Average Annual Growth Rate, the Church Growth Analysts should be able to identify the major factors that are contributing to the growth and/or the decline of a church membership. (See The Church Growth Survey Handbook by Bob Waymire and C. Peter Wagner for further details.)

1.2 Studying Growth Factors in a Region

When interpreting Average Annual Growth Rates for a region, it is more difficult to identify growth factors. It is possible to gain further understanding about Biological Growth of the general population from Government demographic statistics. Government agencies can provide statistics for population by year. It is possible to calculate the Average Annual Population Growth Rate using this information. Government agencies also provide statistics about births, deaths, immigration, and emigration with contribute the population growth or decline.

Sometimes it is insightful to compare the Christian Growth Rate to the Population Growth Rate. Because overall Christian growth is a combination of net population growth (births minus deaths, immigration minus emigration) and net conversion growth (those embracing Christianity minus those leaving Christianity) it is sometimes helpful to subtract Population AAGR from Christian AAGR to estimate Conversion Growth. In other words, we attempt to remove the “natural” or “biological” contribution of population growth to the Christian Growth Rate, thereby getting one layer closer to the Conversion Rate.

  • If the Christian AAGR is greater than the Population AAGR, this tentatively suggests that growth by conversion (though see the following section about “Matters for Caution” for qualifications)
  • If the Christian AAGR is nearly equal to the Population AAGR, this suggests that little Conversion Growth is occurring.
  • If the Christian AAGR is less than the Population AAGR, this indicates decline or that the church is losing ground. Take for example the United States. Operation World indictates that for 2010 the US Population AAGR was 0.97%, but the Christian AAGR was 0.5% and the Evangelical AAGR was 0.8%. Although both the Christian and Evangelical AAGRs are positive, they are less than population growth, indicating a net decline.

1.3 Matters for Caution

The Church Growth Analysis should be cautions to assume that the population growth for the Christian Community is the same as the general population. This is not always so. For example, Pentecostal Families in Romania have a reputation for having larger than average families. The verse, “and the woman shall be saved by childbirth” (1 Timothy 2:15) viewed as a motive by some to justify having large families. Also in cultures where abortion is widely practices, evangelicals who do not abort their children will have larger families. Larger biological families should result in a higher growth rate in such cases if the Church is doing a good job of discipling the next generation. Recognizing this assumption, what initially shows up as “conversion” growth could be a manifestation of larger than evangelical families having children coming to faith, which is technically “biological” or “natural” growth.

Immigration and Emigration also can skew our factor analysis. When large numbers of Christians migrate, especially in regions where Christians are a minority group, either for economic reasons, social instability or direct persecution, at a greater level than the general population, our initial analysis will likely be skewed. Let’s look at two examples.

The countries in the Arabian Peninsula have registered above average growth for the last fifty years according to the Center for the Study of Global Christianity. Initially we may think this is a sign of Conversion Growth, but knowing that these are strong Muslim countries leads us to ask the question, “What is happening here?” The answer is immigration. Workers from East Asia have come to these countries for economic reasons. In some countries immigrants make up 50% of the work force. These immigrants come from Christian countries, primarily the Philippines, and their numbers have greatly increased the number of Christians in these Arab countries. So then, the factor involved in the growth of the number of Christians in these countries is not Conversion Growth, but immigration of Christians.

In Western Africa, Morocco, Tunisia, Algeria and the Western Sahara region have seen significant declines in the number of Christians in the last 50 years. Here the chief contributing factor is emigration. These countries were colonies of France and achieved independence in the late 1950s and early 1960s. The new political situation motivated expatriate Christians to emigrate, leading to a significant decline of Christians in these countries. This larger scale movement of people, however, can hide the number of people accepting the faith from Non-Christian backgrounds.

A wise Church Growth analyst will therefore tentatively hold generalizations drawn about the factors contributing to Christian Growth until they can be verified by additional demographic research or field interviews.

2. Factors Contributing to the Growth of the Number of Churches

Identifying the factors that lead to the growth or decline in the number of churches in a region requires another approach. They most fruitful approach is to conduct interviews with Pastors, Church Planters and Evangelists on the field to discern what they believe were significant factors that led to the increase of churches. From these interviews, case studies can be prepared. Perhaps certain hypotheses will arise that can be tested by further research. Or likely “best practices” will be identified that led to new church starts. By interviewing field workers, the researcher may discover growth factors and best practices of which the individual field workers are unaware. Likewise tentative hypotheses, which the researcher may have ahead of time, may be validated or invalidated by those on the ground. So by working together, greater understanding into the situation is achieved. Here we see that quantitative research (counting the churches) leads to qualitative research (interviews, case studies, focus groups) to discover why new churches were started.