The most obvious effect of the change in policy is that more missionaries will in fact begin their missions at a younger age. Though President Monson didn't say the lower age requirement was meant to be a new standard, as soon as the announcement was made, my sister immediately started discussing whether or not her son should leave earlier on his mission. My nephew is 18 now, and was not planning on leaving until next August when he turns 19, but now he will probably finish out his first year at school and leave in May or June. Had this rule been in effect before he started college, he probably wouldn't have bothered getting a year of school in before his mission (as would have also been the case with myself). I imagine most young men will feel similarly, and as 19 was effectively the standard start age before, 18 will probably be the standard starting age in the future though as President Monson emphasized, this need not be the case for everyone. While we've always had a large contingent of missionaries that went on their missions straight out of high school, I feel like a significant percentage, if not a majority, had attended school for at least a semester before leaving on their missions, just because their birthdays prevented them from serving sooner. (Based on BYU's one-year retention rate, shown below, one might conclude that in fact only 15% of BYU students leave to serve missions after their Freshman year, or roughly 30% of men, meaning closer to 70% go straight out of high school, but this number sounds too high to me, so I need to research more closely how this number is measured before I draw that conclusion.) With a lower age requirement, this will probably become more rare, meaning most missionaries will not begin college until after their mission.
So what will be the effect on LDS higher education? I can imagine several areas where it could have an impact. The first might actually be an increased demand for education at the Church schools. Though I only have anecdotal evidence, my experience has been that there is a greater desire to attend one of the Church schools after a mission than there was before. This was the case with many of my mission companions, who attended community colleges near home (or even prestigious schools like the University of Utah) before their missions, but tried to transfer to BYU after their return because that is where so many of their mission friends were going. Of course many did not want to go through the hassle of transferring to a new school upon their return. If however, they had that interaction with other missionaries that seems to inspire so many to want to attend the Church schools, before they began their education anywhere, it is possible that the Church schools would have been higher on their radar. We might even get more missionaries out of the process, as some young men who wanted to serve missions lose focus during their first year of college, and these added return missionaries would also be more likely to want to attend Church schools. The effect may only be marginal, but even a marginal effect can put a great amount of pressure on the Church system to make room for more students.
The reverse could also be true. Many members prefer the Church schools because they know it will be easy to defer for two years without applying for readmission. Not needing to take a two-year break in the middle of school may encourage many to attend non-LDS schools that would have otherwise brought complications. However, I believe this potential effect will be minimal, leading to a net increase in demand for Church schools. If that demand is not met by the Church institutions through increased capacity, that would definitely play well for schools like Southern Virginia University or the Desert Valley Academy, trying to capture that excess demand. It could also increase the perceived exclusivity of the Church schools, by increasing admission applications, and thereby lowering the acceptance rate (a factor in the US News and World Report rankings).
More than the increased demand however, the area where I expect the change in age requirements to have the biggest impact is in the 6-year graduation rates for the Church schools. While a bachelor degree theoretically only takes four years to complete, it is no secret in higher education that students frequently take longer to finish their degrees. For this reason, the Department of Education tracks four-, five-, and six-year graduation rates. This figure features prominently in the US News and World Report rankings, counting it for 80 percent of the retention score, which is in turn 20 percent of the score for National Universities (of which BYU-Provo is one) and 25 percent of the score for Regional Colleges (which is where BYU-Hawaii and BYU-Idaho fall). The other 20 percent of the retention score is the freshmen retention rate. A significant improvement in the graduation rates could bring all of the Church schools up in their ranking. BYU's six-year graduation rate, while fairly decent, has long been hampered by two effects: woman dropping out of school after getting married, and men taking longer than six years to graduate. While the change in the minimum missionary age will have little direct effect on the former factor, the age change could substantially affect the latter.
For example, it is not uncommon for a student to need an extra semester to graduate due to missing a prerequisite for a class, especially in some of the more structured majors, where one class leads to another. At a normal university, a student taking an extra semester to graduate may hurt the four-year graduation rate, but it does not affect the six-year rate, which is what the US News and World Report ranking takes into consideration. If however that same student also takes two years off in the middle of their schooling (as is the case with the elders), then the extra semester puts them over the six-year mark. Even without needing an extra semester to get the right prerequisites, for many missionaries the timing of the call would also frequently cause them to miss a semester (as was the case with myself--I attended school for a year, left for my mission in October because of a September birthday, and two years later I came home too late to enter for the fall semester, so I lost a semester without experiencing the prerequisite problem). Multiply this by the number of return missionaries at a school like BYU, and this can have a significant impact on the school's six-year graduation rate and potentially its ranking. If however, the clock doesn't start until after one's mission, as I expect will become more the norm at the Church schools with this new policy in place, then an extra semester will not affect the schools ranking as most missionaries won't matriculate until after their missions. We may be able to see some marginal increase in the ranking of the Church schools as an effect.
Of course the reverse may be true of sister missionaries. Though traditionally some sisters have interrupted school to serve, just as often it seems they finish school before serving, both because of the timing of a birthday, and the decreased urgency of serving a mission. If sisters start opting to leave for their missions at the younger age, those who had previously been finishing school before their missions may not be able to. Add to that the fact that more sisters may serve as a result of their lower age requirements, as I suspect will be the case with marriage not being as likely at this younger age, and we will have even more woman interrupting their schooling, which will put negative pressure on the six-year graduation rate. Overall however, I expect the net effect will be positive, as we will probably still see fewer sisters than elders serving overall, and as sisters only serve for 18 months, a lost semester is less likely to put them over the mark as two years does for men.
Obviously it will be some time before we will know the full effect of the change at the Church schools (and for that matter at other schools with a large LDS presence). For now, here are the graduation and retention rates at the three ranked Church schools, as well as some of their peers in the US News and World Report rankings, and Harvard as a reference for what the scores look like at the top of the list.
| US News and World Report Rank | Four-Year Graduation Rate | Five-Year Graduation Rate | Six-Year Graduation Rate | Full-Time Student First-Year Retention Rate | Part-Time Student First-Year Retention Rate | |
| Harvard University (Cambridge, MA) | Ranked #1 National Universities | 87 | 96 | 97 | 98 | N/A |
| Brigham Young University--Provo (Provo, UT) | Ranked #68 National Universities | 31 | 54 | 78 | 85 | 53 |
| Clemson University (Clemson, SC) | Ranked #68 National Universities | 50 | 72 | 76 | 89 | 59 |
| Rutgers, the State University of New Jersey--New Brunswick (Piscataway, NJ) | Ranked #68 National Universities | 53 | 70 | 77 | 91 | 56 |
| University of Minnesota--Twin Cities (Minneapolis, MN) | Ranked #68 National Universities | 46 | 66 | 70 | 89 | 60 |
| Howard Payne University (Brownwood, TX) | Ranked #13 Regional Colleges West | 22 | 35 | 39 | 67 | 17 |
| Menlo College (Atherton, CA) | Ranked #13 Regional Colleges West | 29 | 33 | 33 | 71 | 0 |
| Northwest University (Kirkland, WA) | Ranked #13 Regional Colleges West | 44 | 54 | 55 | 70 | 25 |
| Brigham Young University--Idaho (Rexburg, ID) | Ranked #16 Regional Colleges West | 25 | 41 | 55 | 71 | 55 |
| Brigham Young University--Hawaii (Laie Oahu, HI) | Ranked #17 Regional Colleges West | 28 | 45 | 56 | 58 | 17 |
| East Texas Baptist University (Marshall, TX) | Ranked #17 Regional Colleges West | 27 | 33 | 36 | 64 | 0 |
| University of Montana - Western (Dillon, MT) | Ranked #17 Regional Colleges West | 18 | 24 | 29 | 68 | 75 |
Above data came from the Integrated Postsecondary Education Data System.
