Text messaging won’t help everyone get through college, and cheap interventions won’t solve every problem. But they solve some problems for some students, freeing up time and financial resources for those who need other kinds of help.

Some students need personal counseling to help them balance the demands of school, family and work. Unfortunately, counselors are stretched thin, often carrying caseloads of thousands of students.

Two researchers at Stanford University, Eric P. Bettinger and Rachel Baker, analyzed an innovative counseling program in which a professional academic coach calls at-risk students to talk about time management and study skills. The coach might help a student plan how much time to spend on each class in the days approaching finals, for example. The results are impressive, with coached students more likely to stay in college and graduate. This program is more expensive than texting — $500 per student, per semester — but the effects persist for years after the coaching has ended.

Can nudges help younger children? Susanna Loeb and Benjamin N. York, both also at Stanford, developed a literacy program for preschool children in San Francisco. They sent parents texts describing simple activities that develop literacy skills, such as pointing out words that rhyme or start with the same sound. The parents receiving the texts spent more time with their children on these activities and their children were more likely to know the alphabet and the sounds of letters. It cost just a few dollars per family.

Researchers at the University of Chicago and University of Toronto are also working on methods to develop literacy. Ariel Kalil, Susan E. Mayer and Philip Oreopoulos sent families texts with tips about how to read with their preschoolers. The result was that parents spent substantially more time reading with their children.

Researchers are also testing the effect of giving parents more information about their children’s efforts in school. A school in Los Angeles, in collaboration with Peter Bergman of Columbia University, sent personalized text messages to parents of middle and high school students. The texts told parents when their children did not hand in homework assignments, listing page numbers and specific problems for students to complete. The parents and students responded: Completed homework went up 25 percent and grades and test scores rose. Other forms of communication between the school and parents improved, too, with parents twice as likely to reach out to their children’s teachers.

These light nudges can’t solve every problem, by a long shot. But at a low cost, they can help many students.

Why aren’t schools, districts and states rushing to set up these measures? Maybe because the programs have no natural constituency. They are not labor- or capital-intensive, so they don’t create lots of jobs or lucrative contracts. They don’t create a big, expensive initiative that a politician can point to in a stump speech. They just do their job, effectively and cheaply.