Liquidity stress testing: a model for a portfolio of credit lines

In this paper, we demonstrate how cash outflows due to credit lines can be modeled in a liquidity stress test. Our model is based on bootstrapping from a portfolio time series of daily credit line drawdowns. Key features of our model are (i) that it does not rely on any distributional assumptions or any complex parameter estimation, ie, the model risk is low; (ii) that it is intuitive and straightforward to implement; (iii) that it is very flexible and allows the portfolio's free amount to be reduced during the stress test horizon; and (iv) that it calculates an outflow profile with daily granularity. In a detailed simulation study, we demonstrate the reasonable behavior of the model output toward changes in several input parameters.