Effective timing of tourism policy: The case of Singapore

In this paper, we examine the effective timing of economic policies actions in the tourism industry of a small open economy such as Singapore. The effective timing of policy actions is an open challenge issue to researchers and also a much needed rule of thumb to policy makers and private agents. This paper aims to (a) derive the influencing factors of a tourism demand function and (b) identify the time impact of these factors, thus, allowing the formulations of effective policy actions, by both, governmental tourism authorities and private tourism agents in Singapore. Our findings suggest that tourism government authorities and private tourism agents in Singapore should choose the timing of their actions depending upon the anticipated factor changes and their estimated impact. That is, if exchange rate variability is anticipated then policy actions should start at least twelve months prior to the start of the tourist period. If, a keen price competition is expected to prevail then the best timing of policy actions is nine months ahead the tourism period. If income improvements in origin countries could be expected, then a rather shorter timing action of six months would be available to tourism authorities and private agents in Singapore.     

机构交易行为与中国股市波动实证研究

本文采用2004年1月至2008年6月中国股票市场机构投资者的季度交易数据分析了机构交易与股票价格波动的相关关系。研究发现,机构投资者并非总是具有稳定股市的功能。机构交易对股价波动的影响随着投资者类型、股票市值和流动性水平、市场结构和环境的变化而变化。在"后股改"时代,市场将面临非流通股股本减持的巨大压力,政策制定部门应将机构与中小股东利益集合起来,针对不同市场情况机构买卖单产生的不同影响,制定公平有效的政策和监管机制。     

制导光纤粘结剂特性研究

制导光纤缠绕过程中粘结剂的施涂方式和线包的缠绕质量,取决于粘结剂自身的物理化学特性。做粘结剂的物理化学特性实验,分析其粘度和挥发性。结果表明,实验液体的粘度在喷涂系统的工作范围内,较适合采用喷涂的施涂方式,介于石油醚的强挥发先喷涂固化剂后喷涂硅橡胶和石油醚的混合液,可避免线包因石油醚挥发而胀裂。     

A humanitarian logistics model for disaster relief operation considering network failure and standard relief time: A case study on San Francisco district

We propose a multi-depot location-routing model considering network failure, multiple uses of vehicles, and standard relief time. The model determines the locations of local depots and routing for last mile distribution after an earthquake. The model is extended to a two-stage stochastic program with random travel time to ascertain the locations of distribution centers. Small instances have been solved to optimality in GAMS. A variable neighborhood search algorithm is devised to solve the deterministic model. Computational results of our case study show that the unsatisfied demands can be significantly reduced at the cost of higher number of local depots and vehicles.     

Climate zone crucial for efficiency of ski lift operators

This paper investigates the efficiency of ski lift companies across different climate zones in a group of countries based on establishment data. By a joint estimation of the stochastic frontier production and efficiency equations, the results indicate that ski areas in subarctic climate zones are far more efficient than their counterparts in warmer zones. The presence of a large local market and elevation of the ski area are factors not relevant for efficiency. Output of ski lift operators (companies) increases with the length of ski runs, number of ski lifts, share of slopes covered by snowmaking facilities and availability of fast lifts. Productivity is also significantly higher for ski lift companies owned by a large conglomerate.     

Determining the relationship between ownership and technical efficiency by using a dynamic stochastic production frontier approach

This study adopts dynamic stochastic production frontier approach. Because of the impact of quasi-fixed inputs, airports cannot immediately adjust their production processes. Based on the heterogeneity of public and private airports’ operation models, this study estimates their individual production adjustment speed and their short-run and long-run technical efficiencies to compare transnational airport business performance. The results reveal the differences in the production adjustment of airport groups under different ownerships and performance. Private airports have faster production adjustment, whereas public airports have higher short-run and long-run technical efficiencies. As their primary goal, public airports should strive to increase the elasticity of production adjustment to increase the production adjustment speed, thus improving their long-run technical efficiency. On the other hand, private airports should prioritize eliminating short-run inefficiency to increase their actual output level, thereby improving their long-run technical efficiency.     

随机需求下信誉链融资模式研究

结合报童模型,从定量角度分析了当供应链中各企业未建立信誉链时,供应链总收益会受到零售商的自有资金约束,进一步验证了信誉链融资模式的可行性。此外,研究了当供应链中各企业存在信誉链融资时,建立不同形式的企业联盟对零售商的最优订购量以及供应链总收益产生的影响。     

Index-option pricing with stochastic volatility and the value of accurate variance forecasts

In pricing primary-market options and in making secondary markets, financial intermediaries depend on the quality of forecasts of the variance of the underlying assets. Hence, pricing of options provides the appropriate test of forecasts of asset volatility. NYSE index returns over the period of 1968–1991 suggest that pricing index options of up to 90-days maturity would be more accurate when: (1) using ARCH specifications in place of a moving average of squared returns; (2) using Hull and White's (1987) adjustment for stochastic variance in the Black and Scholes formula; (3) accounting explicitly for weekends and the slowdown of variance whenever the market is closed. (JEL C22, C53, C10, G11, G12)     

The relationship between implied and realized volatility: evidence from the Australian stock index option market

This paper examines the relationship between the volatility implied in option prices and the subsequently realized volatility by using the S&P/ASX 200 index options (XJO) traded on the Australian Stock Exchange (ASX) during a period of 5 years. Unlike stock index options such as the S&P 100 index options in the US market, the S&P/ASX 200 index options are traded infrequently and in low volumes, and have a long maturity cycle. Thus an errors-in-variables problem for measurement of implied volatility is more likely to exist. After accounting for this problem by instrumental variable method, it is found that both call and put implied volatilities are superior to historical volatility in forecasting future realized volatility. Moreover, implied call volatility is nearly an unbiased forecast of future volatility.