We extend the classical risk model to the case in which the premium income process, modelled as a Poisson process, is no longer a linear function. We derive an analog of the Beekman convolution formula for the ultimate ruin probability when the inter-claim times are exponentially distributed. A defective renewal equation satisfied by the ultimate ruin probability is then given. For the general inter-claim times with zero-truncated geometrically distributed claim sizes, the explicit expression for the ultimate ruin probability is derived.
To investigate the impact of microstructure interdependency of a counterparty explicitly, a geometric function is introduced in one firm's default intensity to reflect the attenuation behavior of the impact of its counterparty firm's default. The general joint distribution and marginal distributions of default times are derived by employing the change of measure. The fair premium of a vanilla CDS (credit default swap) is obtained in continuous and discrete contexts, respectively. The swap premium in a discrete context is similar to the accumulated interest during the period between two payment days, and the short rate is the swap rate in a continuous context.
Bai Yunfen1,2 Hu Xinhua3,4 Ye Zhongxing1(1 Department of Mathematics, Shanghai Jiaotong University, Shanghai 200240, China)(2 Department of Mathematics, Shijiazhuang College, Shijiazhuang 050035, China)(3 Guanghua Institute of Management, Peking University, Beijing 100032, China)(4 Postdoctoral Workstation of ICBC, Beijing 100036, China)
