Die Politik steht zurzeit vor einem scheinbar unlösbaren Dilemma. Einerseits sollen die Infektionszahlen niedrig gehalten werden: um die medizinische Infrastruktur nicht zu überfordern, und weil in Abwesenheit einer wirkungsvollen Behandlung Menschenleben gerettet werden sollen. Andererseits wäre aber die Ansteckung großer Teile der Bevölkerung (jünger als 60 Jahre und ohne Vorerkrankungen) vielleicht sogar erstrebenswert, weil die Symptome bei dieser Gruppe ohnehin kaum bis gar nicht wahrnehmbar sind und durch sie eine Herdenimmunität entstehen würde, die systematisch Infektionsketten unterbrechen könnte.

This paper explores how banks react to an exogenous shock caused by Hurricane Katrina in 2005, and how the structure of the banking system affects economic development following the shock. Independent banks based in the disaster areas increase their risk-based capital ratios after the hurricane, while those that are part of a bank holding company on average do not. The effect on independent banks mainly comes from the subgroup of highly capitalized banks. These independent and highly capitalized banks increase their holdings in government securities and reduce their total loan exposures to non-financial firms, while also increasing new lending to these firms. With regard to local economic development, affected counties with a relatively large share of independent banks and relatively high average bank capital ratios show higher economic growth than other affected counties following the catastrophic event.

Understanding how banks react to unexpected events has become a very important economic and social question, especially since the financial crisis (Ivashina and Scharfstein, 2010; Puri et al., 2011). Whereas previous financial crises had largely stayed in the realm of finance, or very limited areas of the economy, the financial crisis of 2007-2008 demonstrated that unexpected financial shocks can have severe implications for the real economy in general, impacting the lives of a large cross-section of the population, for example through general reductions in employment (Chodorow- Reich, 2014; Popov and Rocholl, 2017). This new realization has led to an extensive literature on how banks react to unexpected events, especially if and how they transfer such shocks to firms and households. As a result, understanding exactly how shocks are transferred not only between banks (Popov and Udell, 2012; Schnabl, 2012), but also between banks and firms has become a crucial aspect of financial research (Peek and Rosengren, 2000; Gan, 2007; Ongena et al., 2015; Acharya et al., 2018; Gropp et al., 2018; Huber, 2018). It has returned into focus the idea that a functioning connection between banks and firms constitutes a crucial part of a well-functioning economy. This thesis aims to contribute to the understanding of how this bank-firm relationship functions and what pitfalls it might entail.