Managerial Ethics: An Empirical Study of Business Students in the American University of Beirut

This is a study that investigated the extent of use of the three principles of ethics – utility, morality, and justice – in managerial ethical decision making, in addition to the personal attitude towards them. It involved undergraduate and graduate business students (total N=163) from the Olayan School of Business in the American University of Beirut, Lebanon. Two kinds of measurements were done: self assessment, and testing with the Saschkin’ s Managerial Value Profile (1997). It showed that morality was the overriding ethical principle used, especially in the graduate group (professionals). Business students still believed in the justice system despite the weakness of the country’s law. Utility was the least used, although males were found to be more utilitarian than females. Finally there was no relation between personal attitudes toward the three ethical principles, and the intentional behavior when faced with ethical dilemmas. The findings were discussed and recommendations were given.     

Reinsuring Climatic Risk Using Optimally Designed Weather Bonds

The aim of this paper is to determine the optimal structure of a weather bond, i.e. a bond whose coupons depend on the occurence of a weather event. The stress is put more on the structuration than on the simple pricing of the bond. Therefore, instead of looking only at the bond issue, we consider it as a part of a more general transaction, involving three agents: a firm, which wants to be hedged against its weather risk, an investor, which buys the bond and a bank, which has an intermediary key role. Then, we derive the optimal characteristics of the whole transaction. But the bond structure which is obtained, corresponds to a minimal structure: indeed, only the bond optimal price function and its optimal reimbursement level (amount which is paid back when an event occurs) can be determined while there is a degree of freedom in the choice of the optimal coupon. Therefore, this indeterminacy may be interpreted as a marketing tool and it could play an important role in the negotiation process between the issuer and the investor.     

Observation-driven models for realized variances and overnight returns applied to Value-at-Risk and Expected Shortfall forecasting

We present a new model to decompose total daily return volatility into high-frequency-based open-to-close volatility and a time-varying scaling factor. We use score-driven dynamics based on fat-tailed distributions to obtain robust volatility dynamics. Applying our new model to a 2001–2018 sample of individual stocks and stock indices, we find substantial in-sample variation of the daytime-to-total volatility ratio over time. We apply the model to out-of-sample forecasting, evaluated in terms of Value-at-Risk and Expected Shortfall. Models with a non-constant volatility ratio typically perform best, particularly in terms of Value-at-Risk. Our new model performs especially well during turbulent times. All results are generally stronger for individual stocks than for index returns.     

考虑消费者效用的生鲜品双渠道供应链协调

研究了由一个供应商和一个零售商构成的生鲜品双渠道供应链,构建了受保鲜努力影响的新鲜度变化函数以及受价格和新鲜度影响的消费者效用函数。提出“保鲜成本分担+收益共享”契约,以实现供应链的协调。研究表明,零售商通过分担供应商保鲜努力成本,促使供应商投入更高的保鲜努力水平,从而增加市场需求及利润;供应商通过与零售商分享线上收益,促使零售商承担更多的保鲜努力成本。因此,一定的保鲜成本分担和收益共享比例有助于提高供应链效率。最后采用算例验证了“保鲜成本分担+收益共享”契约对于生鲜品双渠道供应链的有效性。     

Information loss for 2 × 2 tables with missing cell counts: binomial case

We formulate likelihood-based ecological inference for 2 × 2 tables with missing cell counts as an incomplete data problem and study Fisher information loss by comparing estimation from complete and incomplete data. In so doing, we consider maximum-likelihood (ML) estimators of probabilities governed by two independent binomial distributions and obtain simplified expressions for their covariance. These expressions reflect well the additional uncertainty arising from the unobserved data compared to complete data tables. We also discuss an approximation to the expected conditional variance of the unobserved entries and ML parameter bias correction. An empirical example is used to demonstrate the results.     

Incorporating correlation regimes in an integrated stressed risk modeling process

The practice of using stress tests to complement Value at Risk (VaR) estimates suffers from some limitations such as the lack of coherence between a statistical risk measure and a subjective one. On the other hand there is a wide consensus that using the same correlation matrix to design various stress tests is not likely to provide an accurate representation of relationship amongst risk factors in periods of market stress. In this paper we introduce a solution to these problems by explicitly considering different correlation regimes and incorporating the result of the stress test to the traditional market risk measurement models.

Stock returns and expected inflation: evidence from an asymmetric test specification

Previous studies that examined the relationship between stock returns and inflation have used a symmetric test specification, and have reported evidence of an inverse relation. We use an asymmetric model to re-examine this fundamental relationship between stock returns and inflation. We partition the study period into sub-samples of high and low inflation regimes. An inverse relation between stock returns and inflation forecasts is found during only low inflation periods, while a positive relation is detected through high inflation periods. In combination, results from both high and low inflation regimes suggest that stocks have delivered favorable inflation protection.