Hi everyone,I am conducting a research providing empirical evidence to structural credit risk models, such as Merton's. While market (equity and interest rate) factors offer a good explanatory power at a macro/index level, some problems for model specification arise when I look at single-name CDS spreads using firm-specific explanatory variables. I have two questions for you. If you are interested in the second one I can send you details via private message. 1. I would appreciate if you had any links to papers/publications on the subject, although I know the literature is very limited.2. How would you justify that while some issuers' CDS spreads react consistently to equity market factors others seem to be independent of the same factors. Do you think it could be due to a different Debt/Equity ratio among the various issuers, or maybe it could be a problem of low liquidity in CDS prices.Thanks a lot for your time...