Modeling of commercial real estate credit risks

Abstract

Modeling the probability of default for commercial real estate mortgages is more complicated than that for non-commercial real estate loans. This is because borrowers will default only if both the net operating income and the property value fall below the threshold levels. To make modeling more complicated, the property value at the time of default will determine the loss-given default. In this paper, I derive closed-form solutions for the probability of default and the expected loss of commercial real estate mortgages in a Merton framework. The model is in its essence still a single risk factor model, although there is a sector risk factor that influences both the net operating income and the property value. I obtain analytically the economic capital for the corporate-wide commercial real estate portfolio, with granularity adjustments for name concentration and sector concentration.