Credit rating issued by credit rating agencies such as Moody’s and Standard & Poor’s has been largely used as a surrogate measure for the financial and operating conditions of the fi rm. For instance, Sengupta (1998) tests the association between bond ratings and disclosure quality and finds that bond ratings capture the default risk of the fi rm. Copeland and Weston (1988) claim that the rating is a useful source of information provided that on average, the raters provide unbiased estimates of default risk of the firm.
Short-term debt market is also an important source of fund. Diamond (1991) shows that reputation of the borrower affects whether the firm borrows directly or through an intermediary. Crabbe and Post (1994) follow Diamond’s model and investigate the effect of a rating downgrade on an outstanding commercial paper1 (CP). They show that outstanding CP does not fall significantly before the downgrade; however, it declines considerably in the weeks after the downgrade, which means that the downgrade does convey new information to the market. Uday and Nayar (1998) show that the information on lower and/or higher variability of future earnings associated with severe downgrades constitutes new information unavailable to the market prior to the rating change announcement.