Decomposing systemic risk measures by bank business model in Luxembourg

This paper introduces a forward-looking bank-level stress testing framework for a large-scale system to assess three forms of banking system vulnerability– bank capital fragility, bank capital adequacy and bank solvency. Results for Luxembourg are provided with a decomposition by bank business model and domicile type. The paper goes on to assess how these systemic risk indicators are linked to macroeconomic variables, and investigates their predictive power for Luxembourg’s nominal GDP growth one year ahead. Several important findings are documented over 2003Q2 to 2023Q3. First, the systemic risk indicators responded to the main stock market crashes in a timely manner. However, contributions from different bank business models and domicile types varied over time. Second, association with key macroeconomic variables (interest rates, liquidity flow, euro area consumer confidence and business climate) depended on the different characteristics of systemic risk across bank business models. Third, the systemic risk indicators contributed to explaining nominal GDP growth one year ahead. However, the systemic risk component associated with search-for-yield behavior and fee & commission generating activities could also explain nominal GDP growth, suggesting that if banks became more dependent on these income sources, they could create financial stability issues in the long run. Overall, the framework provides a useful monitoring toolkit that tracks changes in forward-looking systemic risk and risk spillovers in the Luxembourg banking sector.