At the height of the "Great Resignation" in 2022, a record-breaking 4.5 million Americans — about 3% of the workforce — quit their jobs each month.

While the wave of resignations has slowed, the trend hasn't disappeared. In October 2024 alone, 3.3 million U.S. workers quit, according to the Bureau of Labor Statistics.

Low pay, long hours, and lackluster benefits are often blamed for employees' departure. But according to a new study by Harvard researchers, high staff turnover is actually being driven by something a lot harder to fix: a lack of career growth opportunities.

After a decade of interviewing and studying more than 1,000 workers — from Fortune 500 CEOs to Chipotle kitchen managers — Harvard researchers found that employees who quit their jobs mainly do so because they aren't making the progress they seek in their careers and lives.

The findings are detailed in "Job Moves," a new book co-authored by Michael B. Horn, a lecturer at the Harvard Graduate School of Education; Ethan Bernstein, a professor at Harvard Business School; and Robert Moesta, CEO and founder of consulting firm The Re-Wired Group.

Quitting and switching jobs, the authors argue, has little to do with career progression as it's traditionally defined — a steady, linear ascent up the corporate ladder. Instead, the authors say, the progress that matters is the intersection of what a person seeks in both their professional and personal life, a definition that can evolve over time.

The four quests for progress

In "Job Moves," the authors identified four consistent patterns for why people quit and switch jobs:

1. To get out of a negative environment: Workers leave when they feel stuck in dead-end roles or managed in ways that drain them.
2. To regain control: Craving more agency, employees seek jobs that offer flexibility, predictability or autonomy.
3. To realign their career with their strengths: People often switch jobs when they feel undervalued, aiming to find roles where their skills are appreciated and utilized.
4. To take the next step: Professional or personal milestones, like finishing school or buying a home, often drive job seekers to pursue better pay, benefits or growth opportunities.

Many people don't fully understand why they're quitting, even after they've handed in their notice, Horn, one of the co-authors of the research, tells CNBC Make It. 

The decision to leave often stems from a "fight or flight" reaction to burnout, a toxic manager, or a role that feels like a dead end, Horn explains.

But without understanding your deeper priorities, you risk repeating the cycle in your next job. Defining your priorities is key to finding a job that fulfills — not frustrates — you. 

How companies can keep workers from quitting

Managers can learn from this research to prevent people from quitting in the first place, Horn adds. 

In "Job Moves," the authors recommend encouraging employees to openly discuss what motivates them — and what might prompt them to leave — during regular check-ins and annual performance reviews with their manager.

Horn and his co-authors found that aligning personal goals with job responsibilities can boost employee engagement and productivity.

"The bosses and HR leaders we spoke with are aware of these issues, but they aren't measuring it on the front end, when someone's hired or first shows signs of struggling," he says. "If you understand what motivates and engages people from the start, you can better support and retain them."

Or, as Horn and his co-authors write in "Job Moves", "To stick around and keep giving their best, people need meaningful work; managers and colleagues who value, respect, and trust them; and opportunities to grow, excel, and advance in their careers."

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