Impact of quality on estimations of hotel efficiency

This paper provides empirical evidence on the impact of output quality on hotel efficiency. It demonstrates how ignoring quality can lead to erroneous efficiency estimates. The study uses stochastic frontier methodology and the model proposed by Battese and Coelli (1995) to estimate the efficiency of 838 hotels in Spain in the period 2009–2013. The key advantage of this methodology is its ability to estimate efficiency and identify factors that explain differences in efficiency in a single-stage sampling procedure. Estimates of cost efficiency, which only include the costs of higher quality, are compared to those of profit efficiency, which not only consider costs but also the revenues generated by higher quality. Results show that quality has a negative impact on cost efficiency and a positive one on profit efficiency. Thus, hotel management should implement strategies that increase the value of their services as a way to achieve sustainable competitive advantages.     

随机数在随机事件与概率教学中的应用探索

本文对在随机事件与概率中的常见问题提出了一种新的借助于计算机实现的解决思路,即通过机器自动产生随机数后构建相应的数学模型,再通过编程计算得到最后结果。该方法既为概率论的教学带来了创新性思维,也为当前的教师提出了新的挑战。     

Measuring systemic risk with regime switching in tails

This paper motivates the importance of modeling nonlinearities in measuring systemic risk. I capitalize this motivation by generalizing the CoVaR approach proposed by Adrian and Brunnermeier (2016) to allow it switching between a high and a normal risk regime filtered from data.. Considering the U.S. large bank holding companies (BHCs), this paper shows that modeling regime changes in tails is capable of capturing both amplification and mean-reversion effects of an adverse shock to a bank's balance sheet on the banking system. Using the Kolmogorov–Smirnov test statistics with and without bootstrapping, I perform the significance test to identify systemically important financial institutions (SIFIs), and the stochastic dominance test to rank the identified SIFIs. The stochastic dominance test raises the concern that the CoVaR measure underestimates systemic risk contributions for SIFIs but overestimates for non-SIFIs. Finally, applying the BHCs' characteristics and housing market price to forecast the regime-switching systemic risk out-of-sample, I obtain from 4- and 8-quarter-ahead horizons a desirable countercyclical, forward-looking measure of systemic risk.     

Simulating Price-Taking

In this article, the author presents a price-takers’ market simulation geared toward principles-level students. This simulation demonstrates that price-taking behavior is a natural result of the conditions that create perfect competition. In trials, there is a significant degree of price convergence in just three or four rounds. Students find this simulation to be a fun, educational experience that adds value to their understanding of competitive markets.     

Selecting make-to-stock and postponement policies for different products in a chemical plant: A case study using discrete event simulation

We present a guideline for selecting the inventory management policy for a specialty chemical plant that produces products with limited shelf life, by producing multiple grades of bulk chemical and packaging them into a large variety of bottles. The policy for each product was selected based on a cost-benefit analysis, using the multiple objectives of maximizing the on time order fulfillment, minimizing the production (cleaning and shelf life expiration) and inventory costs. To generate realistic cost estimates, we developed a discrete event simulation model that included demand variability, planning and scheduling policies, and operational details. We evaluated three different policies: make-to-stock (MTS), postponement, and combined MTS/postponement. We also evaluated different storage media and optimized the number of storage units for products selected for postponement. A combined MTS/postponement policy, in which postponement is applied to products with low to medium demand and high expiration provided lowest costs without significantly impacting the customer on time order fulfillment. For all other products, a MTS policy is applied to maximize order fulfillment on time, reduce cleaning costs and to reduce number of storage units.     

Stochastic Dominance Analysis of iShares

Abstract

Country indices as represented by iShares exhibit non-normal return distributions with both skewness and kurtosis. Earlier studies provide procedures for determining the statistical significance of stochastic dominance measures and the Sharpe Ratio. This present study uses these refinements to compare the performance of 18 country market indices. The iShares are indistinguishable when using the Sharpe Ratio as no significant differences are found. In contrast, stochastic dominance procedures identify dominant iShares. Although the results vary over time, stochastic dominance appears to be both more robust and discriminating than the CAPM in the ranking of the iShares.     

An alternate approach to modeling the slack season provision of guided tours to tourists

We discuss an approach to modeling the slack season provision of guided tours to tourists that accounts for the twin phenomena of stochastic demand and tourist heterogeneity but is different from the way in which this problem has been modeled in the extant tourism literature. Our discussion uses the theory of discrete-time Markov chains and it models the slack season from a tourist demand perspective. Specifically, we first study a case in which the wait plus tour or the excursion time of an arriving tourist is exponentially distributed with a fixed mean. Next, we focus on a scenario in which the excursion time is exponentially distributed with one of two possible fixed means and these two means arise with specific probabilities.     

急诊实践教学方法探讨:PBL联合模拟教学法

急诊医学作为一门临床综合学科,其医学的范畴涉及多个专科,具有急迫性、综合性、实践性、复杂性等特点,实践教学难度较大。我院在急诊医学实践教学中,采用以问题为基础的教学法(PBL)联合模拟教学法,显著提高学生的学习主动性,有效地建立急诊临床思维,培养学生实践能力及知识运用能力,促进急诊医学理论知识的深入掌握,提高教学效果。     

汇改、人民币国际化与汇率定价权 —基于双边随机前沿模型的实证研究

本文通过构建人民币外汇市场中关于人民币汇率定价权力的双边随机前沿模型, 分析了中外定价权差异对于人民币汇率的影响。实证研究表明,中国在人民币外汇市场上较外 部经济体具有更强的定价权力,近期的汇率贬值并非政府操作行为而是市场均衡结果;人民币 国际化和汇率市场化进程可以矫正偏离。本文的政策建议为：（1）继续推进人民币国际化和 汇改市场化进程。（2）进一步提高外部经济体参与人民币外汇市场交易的深度和广度。     

上部覆盖层下伏页岩一类潜在滑坡演化变形机制分析

为研究上部覆盖层下伏页岩这一类型的滑坡失稳变形,需要确定其变形的潜在影响因素,从定量角度上分析这一类型滑坡灾害的变形演化问题。以容县六王镇西流河潜在滑坡为研究对象,借助钻孔勘探、室内试验和地质调绘,详细分析了西流河滑坡的工程地质概况,并推测其可能的变形演化机制,然后利用Geostudio数值软件建立西流河滑坡的渗流模型,模拟其在不同降雨工况下的渗流规律。研究发现:西流河滑坡在持续降雨过程中稳定性系数从1.224逐步降低至1.09,稳定性系数不断下降,滑坡体内由垂直入渗逐步转化沿滑动带稳定渗流;当遭遇极端暴雨情况(50年重现期)时,滑坡体内稳定渗流场显著增厚,饱和滑带土增多,滑坡安全储备达到极限。由此可以得出:上部覆盖层下伏页岩一类滑坡变形演化过程主要分滑坡体上部覆盖层堆积阶段,垂直入渗至页岩富水软化阶段和稳定渗流至潜在滑动带软化蠕变这3个阶段;其中上部覆盖层的高渗透性和下伏页岩的隔水特征是导致页岩风化带软化蠕变和稳定渗流场形成的关键因素。研究结果为上部覆盖层下伏页岩这一类滑坡影响因素的研究提供了一些证据,对研究滑坡演化变形机制具有借鉴意义。