Good luck with the research. This kind of information is desperately needed if we are going to convince corporate interests to make large scale investments in permaculture and food forests. References to pieces of string are not going to cut it with accountants and executives who want to know exactly what their ROI will be. I therefore hope that you will share your research here, so that the rest of us can persuade big investors to sponsor our ongoing efforts.
I too am doing similar research, and so here are a few links that you might also find useful
I hope that this little bit helps.