According to a September 11 survey from SustainAbility and GlobeScan, most sustainability experts rarely or never use sustainability rankings systems for investment, purchasing, or other decisions. The report, Rate the Raters: Polling the Experts 2012, is part of a research initiative to evaluate corporate sustainability ratings and improve their quality and transparency, and found the Carbon Disclosure Project Leadership Index, followed by the FTSE4Good Index Series and the Dow Jones Sustainability Index, to be the most credible of the approximately 108 ratings systems in existence in 2010.