Every year around this time, a new edition of the "100 Best Companies To Work For" is released. These are the companies that go out of their way to keep their employees happy in their jobs.

But is there a direct connection between having happy workers and a company making more money?

One person who may have the answer is Jerome Dodson, the founder of Parnassus Investments, which created a mutual fund that invests exclusively in large American firms proven to have outstanding workplaces.

To Dodson's delight, the Parnassus Workplace Fund proved immediately and enormously successful. Since the fund's inception in April 2005, it has had a 9.63% annualized return. Compare that to the S&P Index which earned just 5.58% during the same period. "Our fund has had returns over 4% better than the S&P Index every year," Dodson noted.

"Eight years later, the performance of the fund confirms what I've always believed. Treating people well and authentically respecting them does lead to far better business performance. We proved it works."

(READ the more from Fast Company)