Barbara Casu

This paper examines the occurrence of speculative price bubbles in a global sample of 43 publicly listed aerospace, defence, and space companies between March 1995 and April 2026. Using recursive bubble detection techniques and a panel probit model, it investigates both the incidence of price exuberance and its key determinants. The empirical results reveal recurrent episodes of speculative bubbles across the sector, particularly during periods associated with major geopolitical conflicts and following the liberalisation of the U.S. space market for private investment. We further find that term spreads, trading activity, geopolitical risk, and global market uncertainty are drivers of bubble formation. These results highlight the need for regulators and market participants to monitor speculative behaviour in innovation-driven industries. Enhanced oversight may help protect investors, promote market stability, and support the sustainable development of the aerospace, defence, and space sectors.

Using a large sample of banks from the Middle East and North Africa (MENA), and African countries, we identify bank business models in the region. We use an Activity-Funding Approach (AFA) and cluster analysis, and we uncover a range of diverse business models heterogeneously distributed across countries. We then evaluate business model change between 2010 and 2019, a turbulent time in many of our sample countries. We find a high persistence of bank business models. Finally, we consider the determinants of bank business models, including bank-specific and macroeconomic factors, and the internationalisation of banks in the region. We find that country-specific characteristics play a crucial role in influencing banks’ choices. Regardless of the country of origin, foreign banks are more likely to diversify their assets and less likely to focus on lending than domestic banks.

This paper investigates corporate reactions to bank misconduct episodes. We test whether more diverse boards have a stronger disciplining effect and trigger “changes at the top”. We consider misconduct fines issued by US regulators to EU listed banks during the period 2009–2018. We find that CEO dismissals are more likely following regulatory fines, but not during the investigation process. Board gender diversity does not seem to impact on boards’ decision to fire the CEO, nor reinforce boards' disciplining effect in the presence of misconduct. The presence of foreign directors and age diversity increase the likelihood of CEO dismissal following regulatory sanctions.

Using a unique proprietary dataset from a large European commercial bank containing granular loan-level information on credit lines to mid-corporate firms, we investigate the bank’s decisions to allow firms to retain existing credit at a time of acute financial instability. Our results highlight the importance of bank-firm relationships during crisis times. Existing borrowers who actively used their credit lines were not rationed, unless they posed an increased credit risk. We do not find evidence of evergreening practices.

In response to post‐crisis regulatory reforms, the European banking sector has undergone significant changes that have led banks to reconsider their strategies, structures and operations. Based on a sample of over 3,000 banks from 32 European countries during the period 2010–2017, we identify banks' business models based on cluster analysis and track their evolution. We then apply a logistic regression and find that banks with higher risk and lower profitability are more likely to change their business model. Employing a propensity score matching approach, we investigate the effect of migration on bank performance and find that changing the business model affects banks positively (i.e. migrating banks increase their profitability, stability and cost efficiency). The effect of migration differs depending on the target business model. When switches are a consequence of being acquired or motivated by regulatory compliance, the positive impact remains.

We investigate the risk effects of bank acquisitions of insurance companies and securities firms between 1991 and 2012 using a newly constructed dataset of M&A deals. We examine risk changes before and after deal announcements by decomposing risk into systematic and idiosyncratic components. Subsequently, we investigate the relationship between risk and diversification by modelling the determinants of risks. We find that bank combinations with securities firms yield higher risks than combinations with insurance companies. Bank size is an important and consistent determinant of risk whereas diversification is not. Our results inform the continuing debate on diversification versus functional separation of bank activities.