Forecasting turning points in tourism growth

Tourism demand exhibits growth cycles, and it is important to forecast turning points in these growth cycles to minimise risks to destination management. This study estimates logistic models of Hong Kong tourism demand, which are then used to generate both short- and long-term forecasts of tourism growth. The performance of the models is evaluated using the quadratic probability score and hit rates. The results show that the ways in which this information is used are crucial to the models’ predictive power. Further, we investigate whether combining probability forecasts can improve predictive accuracy, and find that combination approaches, especially nonlinear combination approaches, are sensitive to the quality of forecasts in the pool. In addition, model screening can improve forecasting performance.     

Forecasting dynamic return distributions based on ordered binary choice

We present a simple approach to the forecasting of conditional probability distributions of asset returns. We work with a parsimonious specification of ordered binary choice regressions that imposes a connection on sign predictability across different quantiles. The model forecasts the future conditional probability distributions of returns quite precisely when using a past indicator and a past volatility proxy as predictors. The direct benefits of the model are revealed in an empirical application to the 29 most liquid U.S. stocks. The forecast probability distribution is translated to significant economic gains in a simple trading strategy. Our approach can also be useful in many other applications in which conditional distribution forecasts are desired.     

坚持马克思主义在意识形态指导地位的根本制度思考

马克思主义为什么行?为什么要坚持马克思主义在意识形态指导地位的根本制度?这是一个非常重大、非常严肃的问题,需要认真回答。在当今世界,马克思主义是世界范围的真实存在,没有任何一种学说能像马克思主义那样深刻地影响并改变世界,没有任何一种理论能像马克思主义那样深刻的影响并改变中国。历史充分证明,马克思主义是中国共产党赢得胜利的"看家本领"。在新时代以习近平为核心的党中央坚强领导下,我们依然要加强马克思主义理论引领和思想武装,依然要坚持运用这个强大的思想武器克服发展中的一系列难题,不断开辟当代中国马克思主义、21世纪马克思主义新境界,不断推进中国特色社会主义的伟大事业奋勇前行。     

Ruin probabilities in classical risk models with gamma claims

In this paper, we provide three equivalent expressions for ruin probabilities in a Cramér–Lundberg model with gamma distributed claims. The results are solutions of integro-differential equations, derived by means of (inverse) Laplace transforms. All the three formulas have infinite series forms, two involving Mittag–Leffler functions and the third one involving moments of the claims distribution. This last result applies to any other claim size distributions that exhibits finite moments.     

基于Moran过程的PPP项目承包商机会主义行为演化动态

在PPP项目中，由于政府部门和承包商的目标不一致以及信息不对称等原因的存在，使得在其全寿命周期过程中，承包商的机会主义行为屡见不鲜。本文基于随机演化博弈理论，建构基于Moran过程的博弈模型，旨在探讨推动PPP项目承包商不采取机会主义行为策略的有利条件。研究表明，承包商数目不断扩大，通过降低承包商之间的举报成本，增大惩处力度，可使降低机会主义行为发生概率的效果显著。进一步，借助数值算例，对研究结果进行验证并给出相应的管理对策。     

On dividends in the phase–type dual risk model

The dual risk model assumes that the surplus of a company decreases at a constant rate over time, and grows by means of upward jumps which occur at random times with random sizes. In the present work, we study the dual risk renewal model when the waiting times are phase-type distributed. Using the roots of the fundamental and the generalized Lundberg’s equations, we get expressions for the ruin probability and the Laplace transform of the time of ruin for an arbitrary single gain distribution. Then, we address the calculation of expected discounted future dividends particularly when the individual common gains follow a phase-type distribution. We further show that the optimal dividend barrier does not depend on the initial reserve. As far as the roots of the Lundberg equations and the time of ruin are concerned, we address the existing formulae in the corresponding Sparre-Andersen insurance risk model for the first hitting time, and we generalize them to cover also the situations where we have multiple roots. We do that working a new approach and technique, approach we also use for working the dividends, unlike others, it can be also applied for every situation.     

Expert opinion and probabilistic volcanic risk assessment

We present data from an international survey of scientists working at volcanic observatories concerning eruption likelihoods. The scientists were asked a range of questions using different types of phrasing. The data suggest that the phrasing of questions affects the ways in which probabilities are estimated. In total, 71% of respondents (N = 70) exhibited some form of inconsistency in their answers between and/or within different question formats. The data also allow for an analysis of the use of scaling in probabilistic assessment, and the use of quantitative versus verbal risk measurements. However, some respondents were uncomfortable with providing any numerical probability estimate, perhaps suggesting that they considered the uncertainty too high for meaningful judgements to be made.     

考虑BI保险的供应链中断模型分析

突发事件引起的供应链中断,会造成供应链成员巨大的经济损失。以一个二级供应链为基础,考虑存在供应中断风险情况下,引入BI保险,建立供应中断下制造商不投保、制造商单独投保、以及制造商和零售商联合投保模型,探究零售商和制造商利润、最优订购量、最优批发价等参数的变化趋势,其理论分析结果为决策部门提供指导。