地方财政行为是否驱动了中国贸易 收支的动态调整*——基于异质性动态调整模型的分析

本文利用1997-2013年中国省际层面的面板数据，借助异质性动态调整模型从动态视角考察了地方财政行为对中国贸易收支调整速度的影响。研究结果显示：（1）平均而言，在地方财政行为的驱动下，中国实际贸易收支向最优水平动态调整的速度约为0045。总体表明，地方财政行为对中国贸易收支的驱动性影响较弱，引致实际贸易收支向最优水平调整的速度也较为缓慢。（2）财政支出分权的强化会制约贸易收支的调整速度，贸易收支调整呈现“相对惰性”。财政收入分权的提高和预算内财政支出的扩张能够加快实际贸易收支向最优贸易收支调整的速度，助力贸易收支实现平滑调整。预算外财政支出和财政收入的变化对调整速度则不会产生显著性影响。（3）贸易收支的调整速度呈现显著的区域异质性。本文的结论表明，现阶段中国要实现贸易收支的平衡调整路径，中央及地方政府必须把握好财政行为与贸易收支的动态联动关系。     

Raising the Bar (3)

This editorial summarizes and comments on the papers published in issue 11(3) so as to raise the bar in applied spatial economic research and highlight new trends. The first paper proposes spatial and a-spatial indicators to describe the networks of airline companies around the world. The second paper sets forth a two-regime gravity-type model with an endogenous threshold parameter to assess the effect of labour market conditions on interregional migration flows. The third paper utilizes micro-data to explain student migration flows to higher education institutions. The fourth paper is among the first to make use of simulation-based location quotients in a multiregional input–output model. Finally, the last paper provides a purely economic–theoretical model on cooperative limit pricing in the context of spatial competition.     

Stochastic seat allocation models for passenger rail transportation under customer choice

We study the seat allocation problem for passenger rail revenue management, in which a rail operator attempts to determine the optimal quantity of seats to be allocated to each cabin class for each train service. We formulate the problem with single-stage and multi-stage decisions as two stochastic programming models that incorporate passengers’ choice behavior. We transform the stochastic models into equivalent deterministic mathematical programs that are easy to solve. Then, we form a variety of seat allocation polices from the optimal solutions to the seat allocation models. A number of simulation tests are offered to test the policies.     

极软表土层支护技术研究

通过对回风斜井的围岩性质及巷道破坏原因分析,结合数值模拟,提出了U型钢支架与短锚杆全长锚固巷道底角加锚索并喷射混凝土封闭围岩支护治理方案。经实验表明,上述方案的实施取得了良好的支护效果。     

Quantitative Analysis of Foreign Trade and Environmental Efficiency in China

This article analyzes the relationships among trade, the economy, and environmental quality in China. First, in the context of these relationships, the Super-SBM model is used to calculate the environmental efficiencies of thirty Chinese provinces and cities to obtain the degrees of regional disparity. Second, China’s provincial panel data from 2003 and 2012 are used to establish an influential factor indicator system of environmental efficiency. A section-weighted fixed effect model then provides insights about influential factors such as spatial heterogeneity. Third, the article establishes a variable coefficient model to identify the relationships among the objects of the study and divides the Chinese regions into four types. The suggestions include enhancing environmental and business regulations to ensure equilibrium between trade, the environment, and local economies.     

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。     

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.     

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.