It's an unexpected finding based on two simple observations. First, most companies tend to raise salaries by only about 5.9% a year. Second, when professionals move to a new company, they usually get a pay rise of at least 10%.

Over time, this difference increases. Someone who changes jobs every few years could be earning at least 50% more after a decade than someone who stays in the same position. The logic isn't limited to employees - it also applies to entrepreneurs.

If you keep doing the same things in the same way, you can expect the same modest growth. But if you want to significantly increase your income, you need to "change jobs" in a broader sense: take on new challenges, approach familiar problems in new ways, or explore entirely new markets.

When was the last time you really changed what you do - or how you do it?