The document discusses how IDCFP uses margins as part of its CAMEL ranking system to evaluate the safety and soundness of banks. Key margins include return on equity vs. cost of equity, operating profit margin, and the standard deviation of operating profit margin over 3-5 years. Banks with negative spreads between these margins and high standard deviations are at higher risk. The document shows that most components of CAMEL, including margins, reached low points in 2005-2006, up to three quarters before the total number of banks ranked below 125 reached its low in 2006, correctly indicating an impending banking crisis.