An excellent talk by a Behavioral Economist, Dan Ariely on job satisfaction. Over the years working in multiple industries and two countries as a freelancer and contract worker, I have observed first hand how the attitude of a company's management towards its employees effects productivity. I've seen it ignored, I've seen it poorly managed and I've seen it genuinely considered and well handled. My observation...it doesn't take as much effort as you think and the answer is not always money.
My favorite part of this study is how the tiniest acknowledgment goes such a long way in making an employee feel appreciated...and it doesn't cost a thing.