Stella 9.1 model can be downloaded from http://forio.com/simulate/jhayward/lbdr-base/model/download/?hard=true.
Model author: John Hayward, Church Growth Modelling.
This model can be used to investigate long term church growth or church decline. The initial population is normalised to 1. The 100 year period is fixed due to limitations in the online simulation.
This model is presented in "A General Model of Church Growth and Decline", Journal of Mathematical Sociology, Hayward, 2005, but in mathematical rather than system dynamics form.
Demographics Model Simulation
Births, Deaths, Reversion and Secularisation
The central hypothesis of the limited enthusiasm model is that conversion growth in the church is driven by a sub-group of church members called enthusiasts. The analogy is with the spread of a disease, where the enthusiasts are "infected" believers passing the faith on to unbelievers who catch the "disease" of religion.
In addition the demographics model includes births, deaths and reversion, allowing for church decline through, lack of child retention, aging and people leaving the church. The unbelievers are split into those open to conversion and those hardened, allowing for secularisation in society.
Opens in separate window: http://forio.com/simulate/jhayward/lbdr-base.