Once upon a time, in workplaces long long ago, companies would offer good employees a lengthy career path--and if employers in return treated their employees well, they would stay for ten years or more. Needless to say, today this reads like a corporate fairy tale, a world that no longer exists. Layoffs have risen every recession since the 1970s, peaking with the economic collapse of 2008, severing the contract of trust between employer and employee. Today we live in a world of constant job "shopping," where the average person stays at a job for only 4 to 5 years.

The business implications of this are massive. The cost of replacing an employee is on average 21 percent of his or her salary, and the opportunity cost of recruiting and training a replacement can be striking. Not to mention, frequent turnover can breed confusion and negativity in the office, making it difficult for a powerful, united team to form and gel.

While it is certainly in your best interest to hang on to employees for as long as you can, you simply cannot expect them to stay forever. Keep your expectations realistic. Start by aiming to increase average tenure by a year or two. Just doing this will add significant value to your company. Take steps to encourage longer tenure by repairing the long-severed contract of trust. Do this by creating a work environment and culture that bonds employees.

Of course, trying to change behavior patterns is no easy thing. You won't create loyalty merely by offering higher salaries than your competitors, or by providing ping-pong tables and free snacks: real structural and systemic changes need to be enacted. At a high level, you build trust by ensuring your leadership acts in alignment with your company values, and that your culture adapts to fit the ever-evolving needs of its employees.

So how do you create a culture that inspires this kind of trust?

Offer Opportunities for Growth

A recent survey of 290 organizations worldwide found that the number one action leaders can take to build trust is to provide tools, resources and learning opportunities for employees. Workers today want to be in environments that contribute to the advancement of their careers; they want to learn. Employees today are more anxious than ever to accumulate skills to protect them against future economic downturns and position them for growth in upturns.

Provide your employees tools to grow within your company, such as training sessions, mentorships, and leadership development programs. Younger employees in particular are hungry for responsibility, so ensure that they are allowed to occasionally take the lead on projects and are made to feel their ideas are just as welcomed as those of more senior employees. This one is simple, folks: if employees know you're willing to invest in their professional growth, they will trust you care about them and will be more likely to stay.

Create an Engaged Culture

It's important that you create an engaged and involved workplace, where employees are encouraged to relate as people (not just workers) to their peers and to management. Have office happy hours, go to a baseball games, start a company book club--it doesn't necessarily matter what you do, as long as you're creating an environment where your team can interact without workplace pressures. Outside the 9-5 grind, you become more than just your job title or your department or a co-worker: you become a colleague worth trusting.

Keep An Open Ear

Many companies survey their customers regularly. But most do not seek, and when they receive it often times neglect, similar feedback from employees. Yet one of the simplest and most effective ways to create trust is to make sure employees know that their voices and opinions are heard. Whether through an internal survey, a suggestions box, or one-on-one chats, take time to ask their opinions!

Then, the single most important thing you must do is to address their feedback openly and honestly. And while you don't have to share confidential information, you do need to view your employees at least as equal stakeholders to the company owners and your customers--as adults who deserve to know where they and the company stand. As we all know, you cannot please everyone all the time, but being open to making changes based on actual employee input and requests will go a long way toward creating a culture of trust.

Of course, even the best workplace with the strongest foundation of trust won't be able to retain employees forever. When someone does decide to leave your company, keep the conversation encouraging and positive. Have goodbye parties. Share the good news of their future next step. Be proud that they are "graduating" from your company better prepared for their future. If you do, they will become proud alumni who will play an important role helping you attract new "students"...and who knows, maybe they will return one day to your company for a graduate degree!