New Delhi, June 16 -- Employee turnover remains a constant challenge for businesses. According to the US Bureau of Labor Statistics, 3.2 million workers quit their jobs in March alone, while the median tenure at a job stands at just 3.9 years. But contrary to popular belief, employees rarely leave solely because of salary, according to a Harvard Business School expert.

Ethan Bernstein, who co-authored the book Job Moves: 9 Steps for Making Progress in Your Career, says most employees engage in "passive job searching" long before they resign.

"People quit jobs all the time. And, in fact, they think about leaving... all the time," Bernstein said.

He argues that managers often make a mistake by assuming employees are not considering other...