An investigation into the quantitative properties of the specific factors model of international trade

This paper presents a specification of a fundamental and popular model in the theory of international trade, the specific factors model. Data from 24 sectors of the Japanese economy are used. Simulated comparative static elasticities extend basic trade theory by uncovering and postulating the following quantitative properties:

1. (i) near factor price equalization with free trade;

2. (ii) high levels of specialization and trade across trading partners; and

3. (iii) concentrated benefits and diffused costs of protection.

Free trade can thus be expected to nearly equalize prices of similar inputs across countries and lead to high levels of specialization and trade.     

Determinants of shrimp importation into the USA: an application of an augmented gravity model

Shrimp farmers in the USA are facing the situation of increased imports resulting in reduced market share, falling prices, and reduced profitability for their farm-raised shrimp. The study examined the determinants of shrimp imports from China, Vietnam, Thailand, and Indonesia using an augmented gravity model of international trade. The results reveal that US imports from the four exporting countries are significantly affected by the GDP of exporting countries, GDP of the USA, exchange rate, unit import value (proxy for import price) of shrimp, and tariff. Tariff policy has implications for the US shrimp industry.     

Microenvironment-specific effects in the application credit scoring model

This paper introduces the improved version of a credit scoring model which assesses credit worthiness of applicants for a loan. The scorecard has a two-level multilevel structure which nests applicants for a loan within microenvironments. In addition, the paper proposes a new type of clustering for a hierarchical two-level structure which is more intuitive and efficient in the application to credit scoring. This structure explores living area-specific effects which are viewed as unobserved determinants of default. The primary benefit of the multilevel scorecard compared to a conventional scoring model is higher accuracy of the model predictions.     

Optimality in an OLG model with nonsmooth preferences

It is a well-known observation that, in the overlapping generations (OLG) model with the complete market, we can judge optimality of an equilibrium allocation by examining the associated equilibrium price. Motivated by recent development in decision theory under ambiguity, this study reexamines the above observation in a stochastic OLG model with convex but not necessarily smooth preferences. It is shown that optimality of an equilibrium allocation depends on the set of possible supporting prices, not necessarily on the associated equilibrium price itself. Therefore, observations of an equilibrium price do not necessarily tell us precise information on optimality of the equilibrium allocation.     

外生单向溢出效应下纵向差异化产品Cournot和Bertrand竞争均衡的比较研究

研究价格(Bertrand)和数量(Cournot)竞争模式下,单向溢出对企业质量选择、利润的影响。以纵向差异化市场结构为例,建立了基于单向质量溢出的不对称寡头竞争模型,运用赋值计算对模型的均衡解进行了比较分析,结论是:1给定溢出因子和学习效应的合理取值范围,领先和跟随企业的质量与利润在价格竞争下都小于数量竞争;2质量间的单向溢出效应、跟随者的学习努力都会导致领先者初始质量的下降,但在价格竞争时,这种逆向选择效应的程度较低;3跟随者的学习激励随着溢出效应的提高而降低,并不受竞争策略变化的影响。这些发现可以解释中国轿车产业竞争模式对合资和自主创新企业关系变化的影响。     

Oligopoly in loan and deposit markets: an econometric application to the Netherlands

Summary This paper presents evidence on the degree of oligopoly in Dutch loan and deposit markets. Using cointegration tests, dynamic specifications are developed for the demand for mortgages, the supply of savings deposits and the associated interest rates. Simultaneous estimation of this model over the period 1957–1990 reveals that in recent years, both markets were significantly more oligopolistic than in Cournot equilibrium. However, competition for mortgages has significantly intensified since the late 1950s. The degree of oligopoly in the market for savings deposits, on the other hand, shows a significant rise over the sample period, probably owing to increased market concentration.This paper, which is a revised version of chapter 4 of my (unpublished) Ph.D. thesis, has greatly benefited from the comments by Lex Hoogduin, Gerard Korteweg and two anonymous referees of this journal. Thanks are also due to Coby Hogewoning and Gwan Tjia, who assisted in collecting the data. All errors and opinions are mine.     

抢抓机遇强市升位加快全面建设小康社会进程

市二次党代会以来,全市各级党组织、共产党员和广大干部群众解放思想,实事求是,抢抓机遇,负重进取,在推进黑河经济社会加快发展中取得了新的业绩.当前最重要的是,充分认识我们全面建设小康社会的现实基础及面临的机遇和挑战,把全市上下的思想统一到抢抓机遇、强市升位,加快全面建设小康社会伟大实践中来.我们要高举邓小平理论和"三个代表"重要思想伟大旗帜,贯彻科学的发展观,实施旅贸牵动、农业强市、工业立市、科教兴市发展战略,打造对外开放新优势,构筑产业发育新格局,建立市场经济新体制,实现兴边富民、强市升位战略目标,加快全面建设小康社会进程.     

航站楼内旅客导向标识的设置与优化研究——以深圳宝安国际机场为例

针对枢纽机场旅客导向标识的科学设置展开探讨.为解决旅客导向标识的空间位置设置问题,建立关键节点选择优化模型,运用数学模型来解决实际问题,并运用LINGO软件进行计算求解.以深圳宝安国际机场T3航站楼为例进行实例分析,对其导向标识目前存在的问题提出优化改进建议,使旅客导向标识更加科学合理、便捷高效.     

The driving forces of China's business cycles: Evidence from an estimated DSGE model with housing and banking

We study the approximate sources of China's business cycles in an estimated dynamic stochastic general equilibrium (DSGE) model with housing and banking. The model replicates well the volatility and cyclicality of key macroeconomic variables observed in the past two decades in China. A host of shock decomposition exercises demonstrate that, among the shocks being considered, both financial and housing shocks are driving China's business cycles, accounting for a particularly large fraction of the variance in most macroeconomic and financial variables at the business cycle frequencies. In particular, the capital quality, housing demand, and loan-to-value shocks display prominent contributions to the business cycle fluctuations. Moreover, there exists substantial interactions between the banking and housing sectors in China, where the collateral constraint and the financial constraint amplify with each other. The results shed new light in the understanding of China's business cycles, and may serve as a useful benchmark for future quantitative analyses of China's macroeconomic fluctuations using DSGE frameworks.     

The Solow model in the empirics of growth and trade

Translated to a cross-country context, the Solow model (Solow,1956) predicts that international differences in steady-stateoutput per person are due to international differences in technologyfor a constant capital–output ratio. However, most ofthe empirical growth literature that refers to the Solow modelhas employed a specification where steady-stateifferences inoutput per person are due to international differences in thecapital–output ratio for a constant level of technology.My empirical results show that the former specification cansummarize the data quite well by using a measure of institutionaltechnology and treating the capital–output ratio as partof the regression constant. This reinterpretation of the cross-countrySolow model provides an implication for empirical studies ofinternational trade. Harrod-neutral technology differences,as presumed by the Solow model, can explain why countries havedifferent factor intensities and may end up in different conesof specialization.     

生产中的客观要素按贡献参与收入分配的依据及其发展趋势

有一种传统的观点,认为马克思、恩格斯在他们社会主义分配观中是否定生产中的客观要素直接参与个人收入分配的。在党的十五大报告指出:在社会主义初级阶段,在社会主义市场经济条件下,要把按劳分配和按生产要素分配结合起来。十七大报告中进一步明确了,要坚持和完善这一分配制度。从而产生了"矛盾论"和"对立论"。本文是在阐述马克思、恩格斯关于社会主义收入分配理论基本思想的基础上,说明在我国社会主义初级阶段把按劳分配和按生产要素分配结合起来是对马克思主义的坚持和发展。并探讨了生产中的客观要素参与收入分配的规律。     

喀斯特石漠化时空变化过程及其驱动因素——以广西来宾市为例

中国西南喀斯特地区石漠化现象日益突出,探究其背后驱动力对于解决该生态问题至关重要。以遥感数据为基础,运用特征空间模型提取2000—2020年典型喀斯特区域石漠化信息,采用地理探测器定量揭示长时间序列石漠化主导驱动因素。结果表明：2000—2020年,研究区石漠化演变呈现“先缓后快”的改善态势;空间上呈现“东西轻,南北重”的分布格局;植被覆盖度、人口密度、GDP和降水量是石漠化演变过程中的主导因子。     

Simple unit root testing in generally trending data with an application to precious metal prices in Asia

This paper proposes a new unit root test that is general enough to accommodate a potentially non-linear deterministic trend function, making it one of the most general tests around. However, the main advantage lies with its simple implementation. In particular, the asymptotic critical values are shown to be “almost” independent of the deterministic trend function, and as a result the test can be implemented without the need for model-specific critical values. The new test is applied to a sample consisting of monthly prices of four precious metals for a number of Asian countries.     

A new ordered family of Lorenz curves with an application to measuring income inequality and poverty in rural China

The most common data source on income distribution in China is grouped data. When income data is in grouped form, some acceptable Lorenz model is needed to approximate the underlying Lorenz curve. This paper presents a new family of Lorenz curves and applies the main model in our proposed family of Lorenz curves to income data for rural China over the period 1980 to 2006. We find that the income share of the rural population at the low end of the income scale has been shrinking, income inequality in rural China has increased over time and that income inequality has impeded attempts to reduce poverty. However, the welfare of the rural population is still improving in terms of the generalized Lorenz dominance criterion.     

On the existence of single-price equilibria in a matching model with divisible money and production cost

The present paper investigates Zhou's (1999) money search model, where money is divisible, agents can hold any amount of money and production of goods is costly, and presents a sufficient condition, expressed in terms of exogenously given parameters, for the existence of single-price equilibria.     

富水岩溶铁路隧道水害成因及排水洞整治效果分析

以既有铁路拱桥铺隧道为依托,通过现场调查、地质分析等手段归纳隧道水害的典型特征,采用仿真模拟方法探究明确暴雨后高水位下隧道结构内力、位移与渗流场的规律特征,并探讨排水洞工程的整治效果。结果表明：连续强暴雨下岩溶地层的地下水位骤升、运营期排水系统的堵塞以及洞内过度泄水措施引发的水害风险是案例隧道水害发生的主要原因;经仿真数值模拟研究,创新提出邻近既有高铁隧道新增排水洞科学合理的空间位置和断面,有效解决运营安全问题;经排水洞整治后,外水压力(尤其是隧底)明显降低,仰拱隆起得到有效控制,即使面临高地下水位仍能保障运营隧道的结构安全与稳定。该研究对于后期岩溶隧道设计施工具有一定的实践指导意义,针对岩溶发育地区创新并提升地下岩溶发育及地下水勘探水平,科学优化隧道结构设计,确保运营安全。     

中国数字经济空间关联网络及其影响因素分析

基于2013年和2020年29个省的数据,用因子模型测算各省数字经济发展水平,在此基础上使用修正引力模型构建数字经济空间关联网络,并深入分析此网络特征。结果表明：中国数字经济发展水平存在差异,东部地区高于中西部地区;中国数字经济空间关联网络密度不断增大;北京、山东、江苏一直是网络的重要输出省份,近年来西部地区在网络中的作用越来越明显;地理位置相邻、贸易开放度和产业结构对网络的形成有显著影响。     

应用Monte-Carlo算法的厦门高崎机场进近管制区容量评估研究

为了对建立了基于性能的导航(PBN)飞行程序的厦门高崎机场的进近管制区进行容量评估。本文采用Monte-Carlo算法,根据厦门高崎机场PBN飞行程序的特点进行了程序分析和数据收集,建立了以中间进近定位点(IF)为原点的Monte-Carlo计算模型,验证了此模型对基于PBN飞行程序的进近管制区进行容量评估的可行性。     

超大跨度变断面隧道围岩力学动态响应与开挖步序优化数值模拟研究——以苏州七子山隧道为例

为了保证超大跨度变断面隧道的施工安全,同时兼顾施工便利性及施工效率,依托苏州长江路南延工程-七子山隧道工程,针对连拱转大跨段开挖过程中拆除或保留临时支撑,以及超大跨度段的是否调整优化开挖步序这两种工况,采用FLAC3D开展数值模拟研究,从围岩位移和围岩应力两方面进行对比分析。研究结果表明：以上两种工况下,围岩位移和围岩应力均存在明显差异;在连拱转大跨段,开挖过程中保留临时支撑围岩所受扰动更小,围岩应力变化较小;在超大跨度段,开挖步序优化方法的拱顶最终沉降值减小了8.60%,仰拱最终隆起值减小了4.01%,左边墙和右边墙最终水平收敛值分别减小了9.42%和16.70%,且优化方法的各测点围岩应力变化相对较小。根据得到的对比分析结果对现场施工提出优化建议：对连拱转大跨段,随开挖过程保留临时支撑,同时为保证施工便利性,采用门式拱架作为临时支护手段;对超大跨度段,采用优化的开挖步序进行施工,可进一步降低围岩扰动,提高施工安全。