Impact of Socially Responsible Investing on Stock Valuations

Does anyone know of any good studies on the impact that socially responsible investing (SRI) has had on “green stock” valuations?

One of the things that I find investing on the public market side is finding mismatches between the value of a company and the price that Wall Street is paying for that company at any point in time - you know stock analysis 101 as preached by Ben Graham, Warren Buffet and their disciples. Well…. to say that I do what Graham or Buffet does would be a misnomer - I have my own methodologies which are a bit more about percieved valuations - but that’s a post for a different day.

What is unique about green stocks, however, is this concept of SRI - people assigning value to a firm and investment that is not driven by the profit motive. Nobody invests in technology companies based on an intrinsic value similar to saving the planet - well at least not that I am aware of (e.g., would gamers buy the stock of a gaming company to keep it in business so they can make more games for them?)…

I am interested to see if SRI throws traditional valuation metrics out of whack when comparing a “green stock” to a non green stock in terms of pure economic return - financial investment goals…