Return on Happiness (ROH)

I had an animated discussion with two of my peers yesterday. 

What is the importance of happiness in the workplace?

Recently, all three of us attended and actively participated in a POSITIVE LEADERSHIP workshop that our workplace offered. The facilitators (Joanna Brandi and Karen Pfeffer)offered many interesting statistics on the importance of positive outlook, happy thoughts, learned optimism, etc. Among references to several other pieces of very compelling research, they mentioned that Tal Ben Sahar's "Happiness" course, is THE most popular course at Harvard. I later Googled and confirmed that this is a true fact.

I wasn't sure whether to be impressed or stunned. People have to go to Harvard to learn about Happiness? It is no longer a basic instinct?

The happiness related statistics have however added credibility to my innate beliefs- people perform better when they are happy. However, my peers questioned, "Are happy employees simply nice-to-have, or is there is a direct correlation between the happiness of employees and the company bottomline? Can the benefits of happiness be measured?"

Is there really such a thing as Return on Happiness?