Corning is carrying a debt/asset ratio of toughly 35% and appears to the able to maintain an EBITDA/interest ratio of over 20%, both of which would seem to imply a"A" credit rating for their bonds. Yet they are ratted only BBB+(a weaker credit rating Why can't we predict a company's credit rating accurately using its debt and liquidity ratios? What additional information might we need to consider? Corporate bonds with credit ratings currently trade at a "speed" (or risk premium) of approximately 1.5% over the yield on US government bonds. What interest rate should Corning expect to pay on new 10-year bond issue if th to maturity on 10-year government bonds is 2.25%