As Mormon leaders seek to add more senior couples to their shrinking missionary force, they’re hoping that less will mean more: less time and expense, more missionaries.

The Church of Jesus Christ of Latter-day Saints has announced that, come September, retired couples will be able to serve international missions for as short as six months or as long as 23 months.

Until the change, missionaries serving outside their own country were required to devote at least 18 months to the assignment.

“We need many, many more senior couples,” LDS President Thomas S. Monson said during the church’s worldwide conference last October.

The shorter term reflects the flexibility already available to seniors serving in their own countries, who already have the option to fulfill six-, 12- or 18-month missions.

The new senior missionary policy comes as the church watches its missionary ranks thin from a high of 61,638 volunteers in 2002 to 52,483 last year. Senior missionaries usually make up about 7 percent of that total, according to David Stewart, author of The Law of the Harvest: Practical Principles of Effective Missionary Work.

Stewart believes the push for more senior couples could be aimed at increasing the number of missions by boosting LDS leadership in countries with little or no Mormon presence.

The decline in missionaries, observers say, is most often attributed to the decreasing size of Mormon families and higher standards to qualify for service associated with the church’s “raising the bar” initiative.

With the help of its new senior missionary policy, the church hopes “to encourage more couples to serve full-time missions and to improve their missionary experience,” according to a press release.

The announcement also changed how much senior missionaries must pay for overseas housing. Instead of footing the entire bill, senior couples now will have their lodging expenses capped at $1,400 a month, no matter where they serve.

Kent Broadhead, who served an 18-month senior mission to Malaysia with his now-deceased wife, believes the new, more flexible approach will appeal to prospective missionaries.

“I really think that you’ll get a volunteer for six (months) that you would not for 18 or 23,” he said.

For his part, though, Broadhead said that if he were able, he would have preferred to have served closer to two years. “There were times that we, if we were five years younger, would have been happy to stay those extra five months.”

Chase Hall writes for “The Salt Lake Tribune.”