Essays on the stability of the banking sector: analyses on accounting data of American banks.

Summary The global financial crisis of 2007-2009 revealed the fragility of modern banks as well as regulatory shortcomings. In the wake of the crisis, the banking sector has undergone significant regulatory reforms: strengthening of micro-prudential regulation, implementation of schemes with macro-prudential objectives, and various initiatives to separate activities. In this context, this thesis, using US data, first attempts to explain the vulnerability of banks by their financial characteristics and organizational structure. Then, the thesis proposes an analysis of the effectiveness of some new tools in the context of reforms. We find the following results: 1) The risk of failure is higher for banks that adopt aggressive strategies during the economic boom and finance themselves with unstable funds. A healthy (well-capitalized and profitable) parent company is a source of strength for bank subsidiaries. This supports the introduction of the countercyclical capital buffer and the liquidity ratio in Basel III. 2) Diversification of activities contributes to the decrease of bank risk, while increasing commitments in volatile non-traditional activities seems to make banks more vulnerable. This supports the need for structural reform for some universal banks. 3) Leverage ratios predict the probability of failure of large banks better than the risk-weighted ratio, while both types of ratios are equally effective in predicting the failure of small banks. This result underscores the importance of strengthening the regulation of systemic banks and implies its implementation.