When the Kentucky governor, Matt Bevin, suggested last month that students majoring in French literature should not receive state funding for their college education, he joined a growing number of elected officials who want to nudge students away from the humanities and toward more job-friendly subjects like electrical engineering.

Frustrated by soaring tuition costs, crushing student loan debt and a lack of skilled workers, particularly in science and technology, more and more states have adopted the idea of rewarding public colleges and universities for churning out students educated in fields seen as important to the economy.

When it comes to dividing the pot of money devoted to higher education, at least 15 states offer some type of bonus or premium for certain high-demand degrees, according to the National Conference of State Legislatures.

But the particular focus on jobs and earnings — originally limited to vocational programs and community colleges — is gaining momentum.

“There’s a deeper question of what public money should be used for,” said Anthony Carnevale, a Georgetown University professor who runs the Center on Education and the Workforce.

A recent salary survey from the National Association of Colleges and Employers, a nonprofit membership organization that connects campus career officers with business recruiters, found once again that new STEM graduates were expected to command the highest overall average salaries in 2016. New engineers, for example, are expected to earn nearly $65,000 a year.