Business case complexity and environmental sustainability: Nonlinearity and optimality from an efficiency perspective.

The question of whether it is possible to "do well by going green" has been debated at length in the literature on environmental sustainability, but no consensus has been reached to date. Building on stakeholder theory in that a firm's environmental sustainability can improve its competitive advantage, this study investigates the impacts of sustainable environmental practices on the competitiveness of 28 international airlines over 2010-2018. First, we use dynamic network data envelopment analysis to estimate airline operational efficiency as a measure of competitiveness. Second, we use a panel smooth transition regression (PSTR) model to test for nonlinearities and regime-switching behaviors between variables. Then, to account for endogeneity bias, we develop and estimate an instrumental variable PSTR (IV-PSTR) model. The empirical results indicate that the relationship between environmental sustainability and competitiveness has an inverted U shape, meaning there is an optimal level of environmental sustainability beyond which competitiveness decreases. Therefore, it is important for airline managers to understand that very high levels of investment in sustainable practices can have more negative effects compared to very little investment. The study concludes by providing implications for theory and practice.

Effects of the COVID-19 pandemic on the US stock market and uncertainty: A comparative assessment between the first and second waves.

This paper makes the first comparative assessment of the impacts of the first and second waves of the ongoing COVID-19 pandemic for the US stock market and its uncertainty. To this end, we investigate the dynamic conditional correlation and the asymmetric impacts of shocks on the correlation between the US and Chinese stock markets before and during the COVID-19 crisis. Furthermore, we analyze and compare the relationship between the COVID-19 pandemic and US returns and uncertainty during the first and second waves of the pandemic. First, we find that the dynamic correlation approach supports the presence of volatility spillovers (contagion effects) between the two stock markets, especially during the rapid spread phase of COVID-19 in the US. Second, the analysis of news impact correlation surfaces shows that the shocks to the US and Chinese markets have asymmetric effects on the correlation between the two markets. Finally, we find a persistent link between US returns, uncertainty, and the COVID-19 pandemic during the first and second waves of the outbreak. Our results prove that the pandemic has shown harmful consequences for financial markets in general and the US economy in particular.

Oil price, US stock market and the US business conditions in the era of COVID-19 pandemic outbreak.

This paper contributes to Covid-19 outbreak impacts literature. We investigate the connectedness between stock market and oil prices under bullish and bearish economic conditions and uncertainty level at different investment horizons. We applied the wavelet framework on daily dataset cover the pre-COVID-19 and COVID-19 period. We find that the linkage between the economic and financial pairs is characterized by significant changes over the time during the sample period, where the huge co-movements has been identified during the pandemic period at the low scale. We show that due to lockdown policy and oil price shock, the stock return decline, the aggregate business conditions reached its lowest level and the uncertainty increase. The result indicates that the COVID-19 outbreak negatively affects the economy and the financial markets and support the sensitivity, especially between oil-stock, and economic condition and uncertainty.