An Empirical Comparison of the Four Channel Flow Model and Adventure Experience Paradigm

The objective of this study was to conduct empirical comparisons between two models of optimal experience within an on-site whitewater kayaking setting using a modification of the Experience Sampling Method. Four concerns are examined: (1) differences in explanatory power between the four channel flow model and the Adventure Experience Paradigm, (2) convergent validity among measures used to determine conditions within these models, (3) differences among measures of perceived challenge and risk between test times of Class I-V river difficulty, and (4) differences among measures of perceived skill and competence between test times of Class I-V river difficulty. Questionnaires were administered in the Cheat River Canyon in West Virginia to 52 whitewater kayakers at eight sites of various levels of river difficulty. Data were analyzed at the experience level, rather than between subjects, using 409 experience sampling observations. Hypothesis testing, performed with statistical analyses (stepwise regression, correlations, and repeated measures ANOVA), suggested that the explanatory powers of the four channel flow model and Adventure Experience Paradigm were similar and indicated support for convergent and ecological validity of measures used to determine conditions within each of the two models.     

Estimation of tail‐related risk measures in the Indian stock market: An extreme value approach

The purpose of the study is to estimate tail-related risk measures using extreme value theory (EVT) in the Indian stock market. The study employs a two stage approach of conditional EVT originally proposed by McNeil and Frey (2000) to estimate dynamic Value at Risk (VaR) and expected shortfall (ES). The dynamic risk measures have been estimated for different percentiles for negative and positive returns. The estimates of risk measures computed under different quantile levels exhibit strong stability across a range of the selected thresholds, implying the accuracy and reliability of the estimated quantile based risk measures.     

中国天然气供给预测及价格改革

中国近几年天然气消费增长较快,并且已经成为天然气净进口国。作为一种可耗竭资源,天然气产量也存在峰值,根据本文预测,中国的天然气产量将大约在2018年达到峰值。而中国仍处于工业化城市化进程中,能源需求刚性增加,天然气消费仍旧会有较大的增加,因而在产量达到峰值之后,将面临大量进口的局面。作为最大的发展中国家,中国天然气的大量进口,将会对国际天然气市场产生一定的影响。更为重要的是,中国的天然气价格仍旧以政府指导为主,大量的进口不仅直接威胁中国的能源安全,价格改革也将面临更大的压力。本文还进一步使用宏观政策工具(CGE)模拟天然气提价的宏观经济影响,研究发现:由于在能源消费中比重较小,因而对宏观经济各变量的影响较小,但由于主要消费部门是居民部门,因此对居民尤其是城市居民影响较大,因而需要采取渐进的改革方式,同时配合一定的补贴政策。     

Policies for managing peak stock of food grains for effective distribution: A case of the Indian food program

The Indian food program has encountered a significant shortfall in storage due to slow expansion of storage facilities in comparison with procurement. The open storage of food grains results in substantial loss and deterioration of quality. While increasing storage capacity is a viable but costly and time consuming option, the adoption of policies for peak storage reduction would go a long way towards effective food grains management. On this background, this study proposes policy adoption for peak storage reduction for effective inventory management. A dynamic simulation model was built by replicating the complex flow process and incorporating the process variability for finding the bottleneck and significant factors. It was found that steep wheat procurement is the critical bottleneck factor for peak storage requirements. Two practical and straightforward, yet effective policies are proposed from the few existing strategies for peak storage reduction owing to the constraints associated with the food program. With the actual data of the food program, reduction in peak stock was estimated for the recommended policies, including the operational cost saving in storage. The practical implications of these policies within the system were also discussed. Through peak reduction, the use of open storage can be significantly reduced, and this leads to better food grains management for effective food distribution.     

Do three-part tariffs improve efficiency in residential broadband networks?

We analyze subscriber usage data from an Internet Service Provider that sells service using three-part tariff and unlimited plans. Subscribers facing three-part tariffs have lower average usage than subscribers on unlimited plans, and differences among heavy users explain nearly all the overall difference. Hence, the three-part tariff saves network costs and narrows the gap, between light and heavy users, in price per Gigabyte used. However, subscribers facing three-part tariffs cut usage similarly during peak and off-peak hours. Since off-peak usage adds no network costs, these off-peak usage reductions lower welfare. Differentially pricing peak usage could further enhance efficiency.     

中国提前碳达峰情景及其宏观经济影响

第75届联合国大会上中国提出了2030年前碳达峰、2060年前碳中和的目标,引领了全球应对气候变化的进程,引起了国内外的广泛关注和热评。因此,对强化的提前碳达峰目标的实现路径及其宏观经济影响研究,具有重要的现实意义和学术价值。本文采用动态可计算一般均衡模型TECGE定量分析了强化碳达峰承诺对我国未来宏观经济的影响。设定了四个情景包括2030、2027、2025和2023年碳达峰,峰值分别为108亿吨、107亿吨、105.8亿吨和103.6亿吨,考察提前碳达峰情景与2030年碳达峰情景相比对宏观经济的影响。研究表明,提前碳达峰情景相比2030年基准情景,越早碳达峰,要求碳税价格越高,GDP和其他宏观经济变量如总消费、总进出口等都有所下降,但是第三产业占比有所上升。越早碳达峰,宏观经济变量下降越多,第三产业占比上升得越多。根据CGE模型对宏观经济影响的定量分析,本文为提前实现碳达峰目标、推进经济高质量发展提出了相关的政策建议。     

Learning from Doing Participatory Rural Research: Lessons from the Peak District National Park

Understanding the socio‐economic and environmental implications of rural change requires the active participation of many research disciplines and stakeholders. However, it remains unclear how to best integrate participatory and biophysical research to provide information useful to land managers and policy makers. This paper presents findings of a RELU scoping study that has formulated and applied a research framework based on stakeholder participation and adaptive learning to model rural change in the Peak District National Park in the north of England. The paper describes a learning process that integrates different types of knowledge to produce future scenarios that describe possible economic and environmental changes due to a national review of burning practices on heather moorland and blanket bogs. We stress the need for using social network analysis to structure stakeholder engagement and outline how a range of participatory approaches can facilitate more inclusive environmental planning and policy development.     

Solving airside airport congestion: Why peak runway pricing is not working

The paper examines why peak runway pricing has never been effectively implemented. Some of the literature discussing the theory is examined to show the basis for the theory and the potential for flaws in practice. Three cases where airports attempted to implement peak runway pricing are analyzed. The findings indicate that there may be some institutional barriers to peak pricing theory that prevent effective implementation. Airports and others seeking to reduce congestion might consider focusing their efforts on working towards providing alternatives for passengers, rather than attempting to use peak pricing as a congestion-reduction mechanism in isolation.     

Constraints affecting mode choices by morning car commuters

In New Zealand as elsewhere, there is an increasing interest in alleviating congestion on the road transport network to improve economic productivity, reduce pollution, and to use the transport network more effectively. Governments enact various policies to encourage car drivers to change their behaviour, but often find that the full impact is not reached. We propose that car drivers have constraints influencing their mode choice for the morning peak period trip (e.g. needing to transport children, needing a car for work during the day). A stated preference experiment conducted in the three largest New Zealand urban areas not only quantifies the likely impact of a wide range of policy tools (both ‘sticks’ discouraging car use, and ‘carrots’ encouraging alternative modes) for each area, but also identifies many significant constraints.     

Peak globalization: Climate change, oil depletion and global trade

The global trade in goods depends upon reliable, inexpensive transportation of freight along complex and long-distance supply chains. Global warming and peak oil undermine globalization by their effects on both transportation costs and the reliable movement of freight. Countering the current geographic pattern of comparative advantage with higher transportation costs, climate change and peak oil will thus result in peak globalization, after which the volume of exports will decline as measured by ton-miles of freight. Policies designed to mitigate climate change and peak oil are very unlikely to change this result due to their late implementation, contradictory effects and insufficient magnitude. The implication is that supply chains will become shorter for most products and that production of goods will be located closer to where they are consumed.