Measuring and disclosing CSR performance

What makes a company sustainable? Or unsustainable? CSR Advisor Mallen Baker talks about what creates irresponsible businesses and also examines stakeholder engagement and why businesses need to measure their CSR performance. This opinion piece in the Ethical Corporation talks about integrated sustainability and financial reporting as an ethical obligation. Also in the Ethical Corporation, Mindy Lubber, President of CERES, a network of investors, environmental organizations and other public interest groups working to address sustainability challenges, argues that companies should be forced to issue non-financial reports. Should CSR/sustainability reporting be made mandatory for businesses or should it be kept voluntary? What are your thoughts?