The Environmental Investment Organisation, generally referred to as the EIO, operates as an independent “out of the box” think tank with a remit to research, propose, and implement effective strategies for improving the ecological and ethical “output” of the Financial System.

It was established in 1996 to work alongside the then newly formed London School of Economics Environmental Initiatives Network (EIN).

Michael Gill, the EIO's founder, published in 1997 a book entitled “Environmental Tracking, Can Investment Revolution Prevent Ecological Catastrophe”. This book asserts that for an average long-term investor, an investment system that causes serious environmental harm is a bad investment. The question since the establishment of the EIO has been how to organise those investors to recognise and use their influence over the investment system.

This is precisely the question that the Environmental Tracking Index Series seeks to address.