Fixed Income Classes Get Indexes with ESG Performance Factors The KLD US Corporate Bond (USCB) Index series is the first US index that applies environmental, social and governance (ESG) factors to fixed income asset classes. Launched by KLD Research & Analytics, Ryan ALM, and Mergent, the indexes are available as 1-3 years, 1-5 years and 1-10 years bond indexes. All three indexes are offered for licensing. The bond indexes were created to help fixed income investors apply ESG factors to their portfolios. The KLD USCB indexes are equal-weighted with a 5% cap per issuer.