I noticed speculation in some news articles and social media posts surrounding whether recent changes announced by the Church regarding children in same-sex marriages would result in a "mass exodus" of members from the Church. Although it is difficult to say at this time how this policy change will affect member activity rates, convert retention rates, and the receptivity of populations around the world to LDS proselytism, past experience from similar announcements regarding changes in church policy suggest little or no change will likely occur. For example, no noticeable correlation occurred in regards to past policy changes and LDS growth surrounding issues such as the Equal Rights Amendment in the late 1970s/early 1980 or Proposition 8 in California during the late 2000s. Worldwide growth measured by several LDS statistical measurements (e.g. increases in total membership, the number stakes, the number of congregations) accelerated during the late 1970s/early 1980s. There was little to no change in worldwide LDS growth trends during the late 2000s. LDS growth rates in the United States within the past 10 years have also appeared stable. Annual membership growth rates have fluctuated from 1.1-1.7%, annual congregational growth rates have averaged around 1%, and steady increases in the number of stakes have occurred every year.
So what affects LDS growth rates? I have found the following factors to be the strongest predictors of LDS growth - whether local, regional, or international: the maintenance of consistently high convert baptismal standards, member-missionary participation, the regular opening of congregations in previously unreached locations, church-planting tactics, self-sufficiency in church administration, cultural conditions (e.g. secularism, nominalism, double-affiliation, ethnoreligious ties), and increasing numbers of full-time missionaries serving.
My prediction is that there will be little to no change in LDS growth rates in the United States or internationally due to the Church's recent policy change surrounding the children of same-sex marriages. Although there will likely be many who disaffiliate themselves from the Church due to this announcement, there will likely be many who return to activity in the Church or join the Church due to media exposure or personal association with active members. Similar findings have been noted in regards to the influence of the internet on LDS growth. LDS growth rates in the United States will likely remain stable or slightly decline in the coming years as a result of the continued secularization of American society and culture, declining birth rates in the Church, persistent problems with member-missionary participation, and full-time missionary over-saturation of some areas.