Some sums:
According to the full report of the survey, which is available as a pdf from
http://b27.cc.trincoll.edu/weblogs/Amer ... t_2008.pdfIn 1990 the survey data indicated 2,487,000 in the US self-identified as Mormon/Latter Day Saint, and In 2008 the survey data indicates 3,158,000 self-identified as Mormon/Latter Day Saint.
Now according to the University of Utah study:
http://www.uhreview.net/articles/12/18B ... -Death.pdfSpecifically, in 2006 Utah had a higher birth rate than
the national average (19.2 births per 1,000 persons
compared to 13.9 per 1,000 persons)2 and a lower
death rate than the national average (537 deaths per
100,000 population compared to 823.2 per 100,000
population as shown in Figure 2)1. Given these two
rates, Utah also has a higher growth rate than the
national average (13.8 persons per 1,000 population
compared to 5.6 per 1,000 population as shown in
Figure 3).
It does not seem unfair to take the overall US Mormon rate of population growth as represented by the Utah figure, does it? That would mean that from year to year you would have to multiply by (1013.8/1000) to get next year's population.
If we do that, starting from the 1990 figure we get this series (rounding down to 1000's)
1990 2487000
1991 2521000
1992 2556000
1993 2591000
1994 2627000
1995 2663000
1996 2700000
1997 2737000
1998 2775000
1999 2813000
2000 2852000
2001 2891000
2002 2931000
2003 2972000
2004 3013000
2005 3054000
2006 3096000
2007 3139000
2008 3182000
3,158,000 is the actual number yielded by the survey estimate for 2008; that is within 1% of the figure given by our calculation.
It does seem clear that unless a difference between immigration and emigration rates by LDS is a major factor (which does not seem very likely), then to within less than 1% any conversions to the CoCJoLDS in the period 1990 to 2008 have been balanced by those leaving the CoCJoLDS.
It does not seem that we are talking about a fast-growing religion except to the extent that LDS tend to have more babies than other people.
Please note that nothing in this post depends on what other groups do. It is only about LDS.