EDI measures to which degree countries have enacted legally binding rules that provide for environmental information collection and disclosure, public participation across a range of environmental decisions, and fair, affordable, and independent avenues for seeking justice and challenging decisions that impact the environment.

It is an average of 3 pillars that measure:
1) the right to freely access information on environmental quality and problems (Access to information pillar);
2) the right to participate meaningfully in decision-making (Participation pillar);
3) the right to seek enforcement of environmental laws or compensation for harm (Justice pillar).

The pillars are calculated by combining 75 legal indicators that are scored from 0 (worst) to 3 (best), producing an overall score that falls within this same range. The pillars are given equal weight when creating an average.