早晚航班对飞行员疲劳程度的影响

航空公司为了提高飞机利用率,导致早晚班的比重明显增加.由于飞行员生物节律的改变,致使其疲劳程度加深.为了保证飞行安全,减缓飞行疲劳,合理排班,需要对执行早晚班的飞行员的疲劳系数进行研究.通过对20名飞行员以及10名飞行学员进行电话访谈,了解到他们早晚班的疲劳程度,进而改进西南航空局可用机组疲劳系数的计算公式,优化了每名飞行员早晚班疲劳系数的计算公式.     

Structural comparisons of networks and model-based detection of small-worldness

In this paper, we consider the problem of assessing the “level of small-worldness” of a graph and of detecting small-worldness features in real networks. After discussing the limitations of classical approaches, based on the computation of network indicators, we propose a new procedure, which involves the comparison of network structures at different “observation scales”. This allows small-world features to be caught, even if “hidden” deeply into the network structure. Applications of the procedure to both simulated and real data show the effectiveness of the proposal, also in distinguishing between different small-world models and in detecting emerging small-worldness in dynamical networks.     

Understanding the Racial/Ethnic Gap in Bank Account Ownership among Older Adults

The observed racial/ethnic gap in bank account ownership among older adults is substantial. We investigate socioeconomic, cognitive, and cultural barriers underling it. As additional potential barriers are accounted for, the residual gaps in financial inclusion with respect to Whites are reduced by 19% for blacks and 46% for Hispanics. We find that citizenship and “taste for privacy” play a limited role for both minority groups, while real asset ownership, health, cognitive ability, and cultural hurdles contribute substantially to the gap. For Hispanics, language barriers explain most of the gap, while neighborhood‐level socioeconomic characteristics are more salient for blacks. We also examine how the racial/ethnic composition of couples influences financial decisions. We estimate a significantly smaller residual gap between “mixed” and white couples than between minority and white couples. We provide empirical evidence suggesting that, other things equal, mixed couples are less concerned with the cultural/psychological barriers facing minority couples.     

Optimal strategy for a fund manager with option compensation

I consider the problem of portfolio optimization for a manager whose compensation is given by the sum of a constant and a variable term. The constant term is a fixed percentage of the managed funds that is payed to the manager independently of his performance. The variable term is a premium that is proportional to the profit earned by the manager over a benchmark at a certain evaluation date. I find the optimal strategy and the optimal portfolio value in the Black–Scholes setting when the benchmark is a linear combination of the risky asset and the money market account.     

Hi-tech start-ups: legitimacy challenges and funding dynamics

Studies on the legitimacy challenges faced by hi-tech start-ups are still scarce, leaving room for research, and policymaking debate. Legitimacy issues may become difficult to face for hi-tech firms in comparison with other start-ups, because they work in an extreme environment where the technological challenges are at the edge of the scientific possibility. The paper proposes a conceptual model to grasp the relevance of three legitimacy drivers of the hi-tech start-ups for investment decisions. We investigated the ability of 30 hi-tech start-up firms to obtain financial resources from the US investors, employing a set-theoretic approach and carried out fuzzy-set Qualitative Comparative Analysis. Our findings clarify that the funding decisions of US investors are driven by the location of headquarter and R&D of hi-tech start-ups and by the educational experience of the founders. Our study has significant theoretical, practical, and policymaking implications.     

Non-linear Gaussian sovereign CDS pricing models

Prior literature indicates that quadratic models and the Black–Karasinski model are very promising for CDS pricing. This paper extends these models and the Black [J. Finance 1995, 50, 1371–1376] model for pricing sovereign CDS’s. For all 10 sovereigns in the sample quadratic models best fit CDS spreads in-sample, and a four factor quadratic model can account for the joint effects on CDS spreads of default risk, default loss risk and liquidity risk with no restriction to factors correlation. Liquidity risk appears to affect sovereign CDS spreads. However, quadratic models tend to over-fit some CDS maturities at the expense of other maturities, while the BK model is particularly immune from this tendency. The Black model seems preferable because its out-of-sample performance in the time series dimension is the best.     

A hybrid information approach to predict corporate credit risk

This study proposes a hybrid information approach to predict corporate credit risk. In contrast to the previous literature that debates which credit risk model is the best, we pool information from a diverse set of structural and reduced‐form models to produce a model combination based on credit risk prediction. Compared with each single model, the pooled strategies yield consistently lower average risk prediction errors over time. We also find that while the reduced‐form models contribute more in the pooled strategies for speculative‐grade names and longer maturities, the structural models have higher weights for shorter maturities and investment grade names.     

Effective HR implementation: the impact of supervisor support for policy use on employee perceptions and attitudes

Abstract

Effective implementation of human resource (HR) policies appears to depend on supervisors’ active involvement in the intervention process. Following recommendations of a recent intervention evaluation framework, we examine how perceived supervisor support during the implementation of a work-life intervention helps to change participants’ perceptions of organizational family supportiveness, and how this ultimately changes participants’ engagement and turnover intentions. A three-wave longitudinal study in a professional services firm (N = 434) that has formally involved supervisors in the process of a work-life intervention showed support for our study hypotheses. Supervisor support for policy use influenced employees’ positive work–home culture perceptions, which in turn strengthened employees’ work engagement and diminished their turnover intentions over time. We discuss practical implications and give recommendations on the future design of HR interventions and related policies.     

The Impact of Unionization Structures with Heterogeneous Firms and Rent‐Sharing Motives

How are unemployment and output affected if wages are set on the sector level rather than firm level? We take a new look at this question, allowing for heterogeneous firms and rent‐sharing motives. Without these motives, employment and output are lower under sector‐level wage‐setting due to higher wage markups. With rent‐sharing motives, however, firm selection is higher under sector‐level wage‐setting, which tends to increase employment and output, thus counteracting the markup effect. Simulations show that the firm‐selection effect decreases the difference between the two unionization structures substantially but it does not change the signs of the effects on output and employment.