Points mechanisms and rewards programs

I study points programs, such as frequent flyer and other rewards programs, as a revenue management tool. I develop a two‐period contracting model where a capacity‐constrained firm faces consumers who privately learn their valuations over time. The firm cannot commit to long‐term contracts, but it can commit to allocate any unsold capacity through a points program. This points scheme creates an endogenous and type‐dependent outside option for consumers, which generates novel incentives in the firm's pricing problem. It induces the firm to screen less ex interim, and to offer lower equilibrium prices, reversing the intuition of demand cannibalization.     

Forecast-error-based estimation of forecast uncertainty when the horizon is increased

Past forecast errors are employed frequently in the estimation of the unconditional forecast uncertainty, and several institutions have increased their forecast horizons in recent times. This work addresses the question of how forecast-error-based estimation can be performed if there are very few errors available for the new forecast horizons. It extends the results of Knüppel (2014) in order to relax the condition on the data structure that is required for the SUR estimator to be independent of unknown quantities. It turns out that the SUR estimator of the forecast uncertainty, which estimates the forecast uncertainty for all horizons jointly, tends to deliver large efficiency gains relative to the OLS estimator (i.e., the sample mean of the squared forecast errors for each individual horizon) in the case of increased forecast horizons. The SUR estimator is applied to the forecast errors of the Bank of England, the US Survey of Professional Forecasters, and the FOMC.     

Trauma epidemiology in Puerto Rico: in-hospital morbidity and mortality from 2002 to 2011

This study aimed to describe the distribution of injury mechanisms and to assess the impact of those mechanisms on the morbidity and mortality of trauma. All patients admitted to Puerto Rico Trauma Hospital (2002–2011) for road-traffic collisions (RTCs, 5,371), gunshot wounds (GSWs, 2,946), falls (2,319), pedestrian accidents (1,652), and stab wounds (SWs, 1,073) were selected. Gunshot victims were 1.19 (95%CI: 1.07–1.33) times as likely as road-traffic victims to have an ISS ≥25. Pedestrians were 1.76 (95%CI: 1.49–2.09) times more likely to have a GCS ≤8 than road-traffic victims were. The risk of dying was 2.64 (95%CI: 2.20–3.16) times higher for gunshot victims and 1.51 (95%CI: 1.23–1.86) times higher for pedestrians compared to patients who had had RTCs. Gunshot victims and pedestrians had the worst clinical outcomes. Accordingly, these patients should receive the most aggressive clinical management. Furthermore, it is imperative to develop public health campaigns on trauma prevention.     

真实型领导与团队创新绩效: 差错管理氛围与特质调节焦点的作用研究

团队创新是企业获取竞争优势,实现可持续发展的重要保证。差错管理氛围和特质焦点提供了理解团队创新的新视角。研究发现真实型领导通过营造差错管理氛围,对团队创新绩效产生正向影响;团队提升型特质调节焦点在差错管理氛围和团队创新绩效间起到正向调节作用。文章拓展了创新、差错管理氛围以及调节焦点等相关文献,并为提升团队创新绩效提供了管理建议。     

Complements or substitutes? A meta-analysis of the role of integration mechanisms for knowledge transfer in the MNE network

The MNE integration literature lacks coherence in the use and effectiveness of different integration mechanisms. In this study, we use meta-analytic techniques to quantitatively synthesize and evaluate the impact of centralization, formalization and socialization on knowledge transfer. Our analysis of 89 independent samples, including 15,506 subsidiaries, shows that socialization facilitates knowledge transfer more strongly than centralization and formalization. Socialization substitutes for formalization’s positive impact, and mitigates centralization’s negative impact on knowledge transfer. We further identify that directionality of knowledge flows is key in explaining the impact of centralization mechanisms. Finally, we point out important systemic problems in current empirical research.     

A mechanisms-based explanation of nutrition policy (dis)integration processes in Uganda

Many African governments have recently invested in strengthened nutrition policy integration to address malnutrition; as a step towards realising the targets of the Sustainable Development Goal 2. Previous studies have identified various factors that enable or constrain how nutrition integration occurs across policy sectors. However, the explanatory value of these studies has remained relatively limited, as the causal processes through which independent variables affect policy outcomes remain unelucidated. This paper addresses this gap by applying a causal mechanisms approach to investigate the processes that explain observed patterns of nutrition policy (dis)integration in different ministries in Uganda. We employed a process-tracing research design to reconstruct the context-mechanism configurations that explain the observed patterns of nutrition integration in Uganda between 2000 and 2017. Data was collected from interviews with 34 respondents, various policy and programming documents, and a focus group discussion. Our analysis reveals that increased nutrition policy integration is explained by four causal mechanisms: (1) international policy promotion; (2) issue promotion by international actors; (3) issue promotion by domestic policy entrepreneurs; and (4) instrumental policy learning. Conversely, two mechanisms led to policy disintegration: (1) leadership contestation; and (2) turf wars. All mechanisms proved activated by configurations of contextual conditions that were time- and organisation-specific. This study showed how a mechanisms approach can provide a more refined understanding of policy successes and failures in nutrition governance. Whereas integration-fostering mechanisms cannot be automated, both government and international actors working to scale up investments in nutrition need to consider and invest in the contextual conditions that allow for sustained nutrition policy integration and, ultimately, a more effective delivery of nutrition services. These include developing leadership for nutrition at different governance levels, domestic ownership and integration-fostering capacity, and supporting policy-oriented learning.     

Semiparametric time series regression modeling with a diverging number of parameters

Variable selection and error structure determination of a partially linear model with time series errors are important issues. In this paper, we investigate the regression coefficient and autoregressive order shrinkage and selection via the smoothly clipped absolute deviation penalty for a partially linear model with a divergent number of covariates and finite order autoregressive time series errors. Both consistency and asymptotic normality of the proposed penalized estimators are derived. The oracle property of the resultant estimators is proved. Simulation studies are carried out to assess the finite‐sample performance of the proposed procedure. A real data analysis is made to illustrate the usefulness of the proposed procedure as well.     

The asymptotic expansion of the regular discretization error of Itô integrals

We study an Edgeworth‐type refinement of the central limit theorem for the discretization error of Itô integrals. Toward this end, we introduce a new approach, based on the anticipating Itô formula. This alternative technique allows us to compute explicitly the terms of the corresponding expansion formula. Two applications to finance are given; the asymptotics of discrete hedging error under the Black–Scholes model and the difference between continuously and discretely monitored variance swap payoffs under stochastic volatility models.     

关于大量程超声波料位计的算法修正讨论

随着现代科学技术的不断提升,煤矿、铁矿、造纸、稀土等行业的自动化水平取得飞速发展,能否稳定、准确、智能地测量料位决定着这些行业是否能够向现代化、智能化发展。测量料位的方法有很多,其中超声波料位计采用非接触方式,能够有效避免光线、粉尘、烟雾和电磁干扰的影响。研究和设计精度高、稳定性好、性价比高的超声波料位计是充满挑战性和具有现实意义的课题。考虑到超声波的传播速度受温度的影响较大,推导出带有温度补偿的速度修正计算公式,并应用在软件算法中;为了进一步提高测量精度,本文还详细分析了超声波传播的实际路径并给出了计算公式。