C53 - Forecasting Models; Simulation MethodsReturn

This paper deals with the comparison of stress tests of institutions using the IRBA method for determining the capital requirement. Different approaches have been used to determine the values of risk parameters PD, EAD and LGD for stres test purpose. Besides the VEC model, which link risk parameters to selected macroeconomic variables, stress tests were constructed using the absolute values model, the relative change model and the VaR model, CVaR respectively. Individual approaches have been tested and compared in two levels. In the first level was stressed only the risk parameter PD, in the second level, all risk parameters were stressed. Empirical analysis on the retail portfolio of retail clients in the Czech Republic during 2005 - 2017 showed some significant differences in the value of capital among some approaches. It has also been demonstrated that by using the appropriate method for stressing only the PD parameter, the same value of capital can be achieved as in the case of stressing all risk parameters simulating the conditions required by the Basel Committee.

The paper deals with the stress test of institutions using IRBA method for determining the capital requirement. The VEC model was used to quantify the links between the macroeconomic variables and the risk parameters of PD, EAD and LGD. In addition to the construction of the VEC model itself, the paper presents the process of selecting appropriate macroeconomic variables and aggregating risk parameters. To design the stress scenario, the method of maximum penalizing the risk parameters of PD was used because of the failure to prove the links between the macroeconomic variables and the EAD and LGD parameters. Empirical analysis of individual variables and subsequent quantification of capital for stress test purposes was performed on the real portfolio of the retail client.