KAITLYN BOURNE, a 21-year-old student from Salt Lake City, Utah, recently returned from 18 months as a Mormon missionary in Atlanta, Georgia. Before going on her mission, she was studying a pre-medicine undergraduate degree at the University of Utah with a full scholarship. But when the Mormon church lowered the age at which young women can go on missions from 21 to 19 at the end of 2012, the idea of going consumed her. “It was a huge commitment, a really hard decision,” she says. “But after months of prayer and thinking about it, I realised I had to do it.”

Ms Bourne’s decision was hard—she had to give up her scholarship. Since returning, she has made plans to go back to university, but instead of resuming her pre-medicine course, she plans to study music at the Hawaii branch of Brigham Young, a Mormon university. Such decisions concern many Utahns. In seeking to expand spiritual opportunities for women, they fear that the Church of Jesus Christ of Latter-day Saints may be inadvertently reducing academic ones.

The drive to include more female missionaries comes as many young Mormons are finding mission work hard to stomach. Missionaries are not allowed to contact home often—a huge challenge for those who grew up with iPhones glued to their palms.

In 2007 just 13% of serving Mormon missionaries were single women. By last year that had jumped to 28%—an increase of roughly 18,000 women. Since missionaries have to pay many of their expenses themselves, they eat into savings that might otherwise be used to pay for college. More important, they eat into time. Christine Durham, an associate justice on Utah’s Supreme Court, worries that by the time young women return from missions, they will be ready to marry, and then within marriage, husbands’ education rather than wives’ will tend to take priority.

The Mormon church promotes marriage as the perfect state of being and forbids sex outside it. The average woman in Utah, where Mormons are 60% of the population, marries at 24, younger than the national average of 27. The state also has the highest birth rate in America. The church stresses that women should be educated, but in practice combining children with full-time study is tricky. Some 70% of Utahn women start college, more than nationally, but less than 50% finish.

The result is that whereas in most of America women are more likely than men to have a degree, in Utah the opposite is true. The gap is particularly striking when it comes to higher degrees: just 8% of Utahn women between the ages of 25 to 64 have a master’s, doctoral or professional degree, a third less than the national figure. This gap shows itself in the workplace, too. The average woman in Utah earns 70% as much as the average man; across America, the figure is 78%.

It is too early to say whether the change in mission rules will affect female graduation rates. But since it was enacted, the number of young women studying at Brigham Young University has plummeted. In 2012, 14,500 female undergraduates were enrolled, almost as many as men. By 2014 that had fallen to 12,000. Whereas in the 1990s women made up 53% of undergraduates at the university, they are now just 45%. Academics are worried.

Perhaps the best hope is that one step back can help Mormon women take two forward. Ms Bourne says that while the decision was tough, “It was the best I ever made.” Julie Roberts, a 24-year-old who went on a mission to Kentucky, says that she too treasures the experience. Both argue that missionary work has made them surer of their faith and their independence. Justice Durham says that despite her concerns, sending women on missions may make them more forceful when they return. Maybe they will insist on marriages that are less bruising to their career chances.