Since the 1980s, thousands of companies have voluntarily issued reports on their environmental performance. Some have commissioned environmental audits that disclose compliance with regulatory requirements and long-term environmental liabilities. Others have committed to environmental "codes of conduct" -- sets of general principles and overarching goals meant to guide a company’s day-to-day practices. Still others have sought to have their products or the way they run their businesses certified by independent third parties as "environmentally sound."

This growing array of voluntary initiatives provides routes to accountability that businesses themselves find more acceptable. To some extent, adoption of these voluntary practices reflects the acceptance by many companies that they must address public expectations of their behavior forthrightly. On the positive side, evidence shows that some voluntary measures have helped reduce pollution, increase company eco-efficiency, or boost competitiveness. They may also have helped businesses avoid more costly regulation and saved governments some regulatory expense (Schmidheiny et al. 1997:148).

But in practice, voluntary initiatives have several weaknesses that limit their ability to drive better environmental performance on a significant scale. Despite huge growth in voluntary programs of disclosure and environmental certification, the number of corporate sectors and companies involved remains relatively small (Utting 2002:63). Codes of conduct and environmental certification schemes often lack clear targets, measurable outcomes, or deadlines for improvement. Corporate reports issued voluntarily may supply a wealth of data, but not necessarily the information that regulators, investors, consumers, and communities need to assess company performance, or to hold corporations accountable for their commitments to good environmental citizenship.