LINCOLN, Neb. (AP) — A persistent shortage of substitute teachers is creating challenges for Nebraska and Iowa school districts, and lawmakers who want to address the issue are still trying to pinpoint a solution.

Lawmakers from both states said the problem is most severe in rural districts. In Nebraska, senators convened a hearing last month to look for ways to minimize the time regular teachers spend out of the classroom.

The shortage is driven by a combination of trends, including mandatory teacher training during the school week and family leave policies that allow regular teachers to take off as much as 12 weeks at a time.

Iowa and Nebraska’s low unemployment rates plays a role, because fewer workers must settle for part-time jobs.