A causal analysis of missionary and membership growth in the Church of Jesus Christ of Latter-day Saints (1830-1995)

Although a strong positive correlation exists between missionary and membership growth (r = .99), correlation is not causation. To establish causation, in addition to demonstrating relationship, nonspuriousness and temporal precedence need to be demonstrated. The techniques and tools of time series analysis were used to assess possible causal relationships between missionary and membership growth. The deterministic and stochastic components of both the missionary and membership time series, which may lead to spurious relationships, were removed using four different modeling techniques. The resulting residuals were cross-correlated. There was strong evidence of bidirectional causality. Increases in missionaries lead to increases in membership six and 14 years later. Increases in membership lead to increases in missionaries eight years later. Although technically ambiguous regarding causal direction, the lag zero correlation also was found to be significant and was interpreted as indicating that missionary growth produced membership growth. While a theoretical explication of the causal processes involved still is needed and further research is warranted, initial evidence substantiating complex causal relationships between missionary and membership growth was presented and discussed.