3 Smart Investments to Help You Retain Millennial Employees So many millennials seem to leave in a year or two, taking your investment in training and development with them. Here's what to do to keep them engaged.

A common refrain I hear from business leaders is, "We hire them, we train them and then they leave!" Those leaders are referring to millennials, who have been a management punching bag for a while, and are starting to be joined by Gen Z.

Related: This Is How to Train Your Managers to Boost Engagement With Millennials

Turns out these leaders aren't wrong: Gallup research has found that millennial turnover is over three times the rate of other generations; Gallup also estimates "that millennial turnover costs the U.S. economy $30.5 billion annually."

The thing is, though, that many millennials actually want job security. According to a recent study commissioned by Bridge, "nearly 90 percent of millennials are looking to grow their careers within their current companies." So, that means that as an owner, you've got plenty of opportunity to retain them if you're willing to make the effort. Many employers assume they'll have to offer Silicon Valley-style perks to retain millennial employees, but that's not necessarily true.

Alternately, here are three ways you can retain your staff by making smart investments in more meaningful work experiences:

Invest emotional energy and personal attention in your employees.

If your employees think you're not interested in them personally, they'll check out and look for something or someone else. According to the Qualtrics-Accel Partners survey, fully 81 percent of millennials surveyed said that for them, the most important management quality is to be trustworthy. In other words, they're counting on you to be a real person, and to treat them as real people, too -- not just a cog in the machine.

Related: 5 Scientific Suggestions for Curbing an Employee's Sense of Entitlement

So, to help you pass millennials' sniff test, share aspects of your own work and leadership journey, including mistakes you've made along the way.

And because gaining trust can't be done with one-way communication, ask for your employees' observations about what is and isn't working well in the business. Then apply their feedback where you can, and make a point to show off the outcomes of their input. At the offices of a client of ours, we saw a noticeable difference in turnover on a team whose members felt their ideas never got any traction with their manager, versus on a team whose vice president spent significant time explaining how things worked.

This executive asked for team members' views, then took positive action whenever she could.

Invest organizational effort in developmental experiences.

The 2016 Deloitte Millennial Survey showed that those millennials most likely to remain longest with their organizations were those who had a sense of purpose and were satisfied with their variety of experiences. So, to create those conditions, acquaint your millennials with aspects of the organization outside their current job role, and create more opportunities for interpersonal relationships that will help them feel involved and important.

How to do that? Create concrete opportunities in which millennials can learn directly from their colleagues, customers and every other constituency their work will affect or already relies on. Cross-training, job-shadowing and participation in ad hoc working groups all provide valuable awareness of the needs and preferences of others, as well as how their roles integrate and align.

One of my clients has a global learning team whose members work on complex projects together. New members rotate in and out so that people in each location can gain exposure to the workings of other parts of the company, and build a foundation for open, candid relationships for the future.

For younger staff members, this approach presents wonderful opportunities to find mentors and build networks throughout the organization, thus expanding their subsequent opportunities to join meaningful projects. Similarly, as CNBC has reported, EY (formerly Ernst & Young), one of the four largest accounting firms, sends millennials out to meet with clients as early as possible, so they can feel that they're contributing to the mission and the bottom line right away.

Invest in tailored performance-evaluation and career experimentation.

Traditional annual reviews don't satisfy millennials' desire for rapid performance feedback; in fact, 74 percent of those polled in the Trinet Perform study.reported feeling "in the dark" and therefore more inclined to job-hop.

Millennials want to know how to think about what comes next and what they need to do to move forward, rather than dwelling on past mistakes. Accordingly, long-standing workplace practices like performance critiques, post mortems and annual reviews are shifting.

New trends include pre mortems, which assess what could go wrong; retrospectives, which highlight the positive as well as the negative; and frequent behavioral feedback, emphasizing how to make things better in the future. To take advantage of this tendency, one of my clients added daily stand-ups and weekly one-to-one meetings to stay close to, and engaged with, his millennial staffers.

In addition, some of my clients are adding additional job levels, like senior associate, senior manager and senior director, providing halfway steps between levels, to let employees test whether they like the ladder they're on and can handle the additional responsibility.

In another case, where I worked with a promising young person, I laid out and contrasted all the possible next steps, including alternative work groups, differing time horizons and commitments in each role and additional education. Even a few years ago, no employer would have allocated his or her coaching budget this way; but in today's world, coaching can pay off in staff retention and engagement.

Overall, when it comes to your younger employees, if you're willing to put in the personal time and attention, set the organization up to connect and engage and encourage individual career choice and development, you're more likely to find yourself in a welcome minority.

Related: How to Engage Employees Through Your Company Vision Statement

This is the minority of companies that keep younger employees longer and more productively, paving the way for stronger customer relationships, better internal functioning and a reputation as an employer of choice.