Pro-family ethic keeps baby boom right on booming

While most US educators worry about dropping school enrollments, Salt Lake valley has a reverse problem: a giant-size baby boom.

Birthrates are roughly double the national average, giving Utah the lowest median age in the country - 24.2 years - compared with a national average of more than 30.

''The demographics of Salt Lake and Utah are unlike any (other) part of the United States,'' says R. Thane Robson, a University of Utah economics professor.

The reason? The Mormon church emphasizes large families. ''While everyone else in the country has been quitting, the Mormons were just getting started,'' Dr. Robson said.

During the 1970s, Utah was the fifth-fastest-growing state in the union, with a 37.9 percent jump in population; a similar increase is projected for this decade. But unlike other Sunbelt and Western states that saw swarms of immigrants, Utah's increase was largely from births.

''If Utah was a developing country, we would be accused of having a population crisis,'' a business leader said.

With over half its population under 25 years old, Utah faces a crunch on its education budget. A third of the state's population is involved with schools daily, from students to dishwashers. The University of Utah, for instance, expects student enrollment to jump 50 percent by 1988. ''We're just going to have to figure out what to do with all those new students,'' university vice-president R.J. Snow says.

The fecundity of Mormons also worries state officials. Is Utah ready for a baby boom? ''No!'' says Gov. Scott Matheson emphatically. ''The flow of young people into the schools is massive. We've got to decide what the trade-offs are now.'' An estimated $1.7 billion in new schools is needed by 1990. The state already spends more dollars per taxpayer on education, but less per student, than most other states.

Up to the 1970s, the Salt Lake area - where almost 80 percent of all Utahans live - saw a steady migration out of the state. That's turned around now: People are moving back into the state either to take advantage of new job opportunities or to retire in the dry and pleasant Utah climate. But most of the state's recent population rise is accounted for by new babies, not movers-in.