The U.S. job market has scarcely been stronger. The latest Labor Department data show an unemployment rate of 3.5%, near a 50-year-low. There are far more open positions — around 10.7 million — than there are people looking for work.

Attracting and retaining employees amid these conditions isn't easy. Today's workers, particularly younger ones, want more than a job that just pays the bills. They want to join organizations that value, and are willing to invest in, their personal and professional growth.

Employers who want to keep their operations humming will need to make such "upskilling" initiatives a priority.

Companies upskill by training employees so they can be more productive in their current roles or be promoted into new ones. It's an effective way to help companies grow organically and improve employee satisfaction.

That's especially true since the start of the pandemic, as working people's environments and expectations have drastically changed. About 20 million people quit their jobs in the first five months of this year, according to the Bureau of Labor Statistics. That's about double the number of people who quit over that period ten years ago.

Why are so many people leaving their jobs?

"Low pay, a lack of opportunities for advancement and feeling disrespected at work," according to a Pew Research Center survey in March.

Upskilling can address all three of these issues. By investing in workers' skills, employers prepare them to do better work and help them become more secure in the skills they have. Early and ongoing training builds confidence and lowers workplace anxiety and dissatisfaction.

To expand access to opportunities for advancement, meanwhile, companies need to educate their employees both inside and outside the workplace.

Starbucks, for example, offers free bachelor's degree programs with Arizona State University online that are flexible for part-time and full-time workers. Disney reimburses 100% of tuition costs within its network of affiliated schools.

At Abbott, we do both with our FreeU program, which helps employees earn bachelor's degrees at no cost and on flexible schedules. We're also piloting an apprenticeship program, where we'll partner with community colleges to offer students real-world experiences that will equip them for success after graduation.

Upskilling employees across departments is another way to improve workplace mobility. Walmart began cross-training employees during the pandemic in order to give them more ownership of the work within a given area. By empowering employees to take on leadership roles within their departments, the approach also sets them up for career advancement and higher pay.

Abbott's cross-department training takes the form of "learning gigs," where employees volunteer for special assignments to gain experience in departments they might want to work in one day.

For example, someone on our operations team in Illinois might advertise internally that she's looking for help managing inputs for one of our diagnostics factories. One of her colleagues in Brazil could volunteer for the gig and gain experience that might help him oversee factory operations in his home country down the line. It also affords our employees with the unique opportunity to meet colleagues in other countries and expand their knowledge of our global business.

Upskilling efforts like these are crucial not just to attracting and retaining workers but to creating leaders who will eventually run a company. The sustainability of an organization — its very survival — depends in large part on developing talent and promoting from within. After all, recruiting and hiring employees, especially those at upper levels, can cost thousands of dollars.

The payoff for upskilling efforts can be huge. A recent study by MIT Sloan School of Management found that companies with upskilling programs report significant returns on investment -- up to 250% higher.

Companies routinely say that their greatest asset is their people. By investing in upskilling, employers can show that they mean what they say -- and allow the great employees of today to become the great employees of tomorrow.

Mary Moreland is executive vice president of human resources at Abbott.