The four general categories are (1) scale and diversification, (2) operational efficiency, (3) margin stability, and (4) leverage. Larger companies and those with more different product lines and greater geographic diversification are better credit risks. High operating efficiency is indicative of better credit risk. Stable profit margins indicate a higher probability of repayment and thus, a better credit risk- Firms with greater earnings in relation to their debt level are better credit risks. While the availability of collateral certainly reduces lender risk, it is not one of the general categories used by credit rating agencies to determine capacity to repay. Specifically, they would consider (1) several specific accounting ratios and (2) business characteristics. The availability of collateral falls into neither category.