Analysis of existing data on LDS member activity from official sources, national censuses, and other existing sociologic data lead to several key conclusions.
First, less than half of individuals claimed as members by the LDS Church worldwide identify the LDS Church as their faith of preference. The percentage varies from the mid-sixties in the United States to 20-27% in Latin America. The low correlations between official membership claims and self-identified religious affiliations in Latin American nations that account for the majority of non-U.S. LDS membership make it statistically impossible for this ratio worldwide to reach the 50% threshold. If neighboring nations with similar political and cultural circumstances demonstrate trends similar those of larger nations from which data are available, approximately 40% of individuals claimed as members by the LDS Church worldwide identify the Church as their faith of preference.
Second, as actual member activity and participation rates are always lower than self-identified rates of religious affiliation, existing data suggests that the number of Latter-day Saints attending church worldwide on an average Sunday cannot exceed 30% of official membership figures, and is likely closer to the upper twenties. Idiosyncratic definitions of "activity" that include members who attend irregularly or who identify the LDS Church as their faith of preference may lead to slightly higher figures not to exceed the 40% ratio of self-identified religious preference to official membership statistics, but such broader definitions are not reflective of weekly church attendance.
Third, the LDS missionary program has not been as effective in either the United States or in international areas as one would like to believe. Although convert baptisms outpace baptisms of member children by a factor of nearly three to one worldwide and are near parity in the United States, more than three-quarters of Americans identifying themselves as Latter-day Saints in independent sociologic studies are lifelong members. Such figures imply very high attrition of U.S. converts, as most nominal converts fail to become active or participating members. Data from Latin America, the Philippines, and other international areas demonstrate that three quarters of converts are entirely lost to the church within a year after baptism. While raw LDS membership numbers may appear impressive on paper, these numbers have only a fractional relationship to the far more modest number of converts who have experienced a genuine, lasting, and life-changing conversion and who experience the blessings of active participation in the work of the Church. The available evidence suggests that the primary responsibility for these fractional retention rates lie with quick-baptize tactics which have traditionally focused more on meeting monthly baptismal goals than on ensuring that converts have been adequately prepared for baptism. Recent missionary program changes with the "Preach My Gospel" manual have led to at least some improvements in these trends, although significant problems and challenges remain unaddressed.
Finally, great care is needed in researching, analyzing, and reporting activity and retention data. Pitfalls abound, and available data must be carefully scrutinized to ensure that it is well understood before valid conclusions can be drawn.