This paper examines the theory of commercial mortgage default and test
s it using a data sec of 2,899 loan histories provided by a major mult
i-line insurance company. A default model is estimated which relates s
ubsequent default incidence and timing to contemporaneous loan term, b
orrower, property and economic/market conditions. Maximum likelihood e
stimation is used to estimate a hazard function predicting conditional
probability of default over rime. Results confirm many expected defau
lt relationships, in particular the dominance of loan terms and proper
ty value trends over time in affecting default. The effectiveness of t
he model in discriminating between ''good'' and ''bad'' loans is explo
red. Implications for underwriting practice and credit risk diversific
ation are noted. Finally, suggestions are made for extending these res
ults in pricing applications.