城市轨道交通大小交路结合快慢车开行方案优化

城市轨道交通线路可以实行大小交路的开行模式,以克服断面客流不均衡导致的能力浪费,而这种模式使长距离乘客的出行时间增加,可以在列车开行大小交路的基础上考虑开行快慢车。以乘客出行成本与企业运营成本最小为目标,考虑列车停站时间与客流需求的关系,将停站时间纳入乘客出行成本,建立双目标非线性整数优化模型,求解乘客与运营企业的成本博弈均衡点。通过算例验证模型的有效性,结果表明,相对于大小交路嵌套的运营模式,实行"大小交路+快慢车"的运营模式可以有效降低乘客出行成本与企业运营成本。     

考虑换乘费用的城市公共交通票价优化

换乘所产生的附加费用,如时间和票价等,导致配流影响因素产生变化,如果沿用传统方式将降低预测精度和可靠性。通过引入换乘次数和方式等因子计算出行等待、乘车、换乘及风险评估预留时间等,定义广义出行费用与计算方法;建立双层规划模型求解最优票价,最后通过算例分析弹性出行需求、换乘费用、票价之间的关系。计算结果表明,换乘费用对出行需求的影响小于票价优化对出行需求的影响,优化票价随换乘费用增加而加速降低,为公共交通票价优化提供研究依据。     

金融发展、制度演进与经济增长

根据内生增长理论,确定经济增长的影响因子,然后着重考察制度因素,将其与金融发展的指标变量建立回归模型,以此深入分析金融发展作用于经济增长的制度演进渠道.研究结果表明:无论在长期还是短期内,金融发展对制度演进的影响较大;并且金融中介对制度演进的作用明显要大于金融市场.     

科普对经济增长贡献率的估算

本文从技术进步对经济增长的促进作用方面探讨了科普投入产生的经济效益。采用柯布-道格拉斯生产函数,选取1990—2007年我国GDP和各生产要素投入等统计数据,从定量角度检验了技术进步对经济增长的贡献,从而得出科普投入的贡献率。结果证实,科普投入对我国经济增长具有明显的促进作用。     

Aid econometrics: Lessons from a stochastic growth model

This paper evaluates the standard empirical methods employed in the study of foreign aid, when the data generating process is a calibrated stochastic growth model in which aid recipients make optimal investment and consumption decisions. When recipients receive a stochastic flow of aid and wish to smooth consumption, standard methods fail to distinguish between the response to transient and permanent aid shocks, and hence yield misleading results concerning the object of interest to policy makers: the long-run impact of aid.     

我国居民杠杆率现状及影响因素研究

近年来,我国居民部门杠杆率的快速上升引起社会各界关注。本文使用货币信贷和城镇储户调查数据,对我国居民部门杠杆率和偿债能力现状进行了分析,并运用各省住户贷款数据计算各省的居民杠杆率,使用面板数据模型对居民杠杆率上升的原因进行了实证分析。结果表明,房价的快速上涨和住房销售的增长都对居民部门杠杆率的上升有显著正向影响,其中房价上涨的影响程度更大。此外,金融发展水平和老年人抚养比对居民杠杆率有正向影响,少年人抚养比对居民杠杆率有负向影响。     

HOW CAN PUBLIC SPENDING HELP YOU GROW? AN EMPIRICAL ANALYSIS FOR DEVELOPING COUNTRIES

Although many studies indicate that both the level and composition of public spending are significant for economic growth, the results in the empirical literature are mixed. This paper suggests that the country sample selection and expenditure classification are important in explaining these conflicting results. The empirical analysis shows that the link between growth and public spending, especially its core component, is strong only for countries with macroeconomic stability and fast GDP per capita growth dynamics, which are also capable of using public funds for productive purposes.     

Identifying the internal structure evolution of urban built-up land sprawl (UBLS) from a composite structure perspective: A case study of the Beijing metropolitan area,China

Differences in the internal composite structure during urban built-up land sprawl (UBLS) will generate different effects, and thus, a city’s spatial structure has important bearings on urban sustainability. This study investigates the spatial and temporal characteristics of the internal structure and allocation relationship of UBLS using multivariate spatial correlation and the Weaver-Tomas composite coefficient based on site data of granted built-up land parcels. Moreover, the composite structure evolution process of UBLS and its driving mechanism are examined in this study. The results reveal that the amount structure of the three types of UBLS (i.e. industrial land sprawl, residential land sprawl and commercial land sprawl) tended to be balanced during the study period. Following the transformation and upgrade of the urban industry structure, the overall composite structure of UBLS ranged from single residential land-use structure (Res.) to industrial-residential land-use structure (Ind.-Res.) In the early period of land marketization, the marketization land granting mechanism caused low spatial correlation between the various types of UBLS and a single composite structure, i.e. Res., single commercial land-use structure (Com.), and residential-commercial land-use structure (Res.-Com.). Subsequently, a dual-driving force including the market economy and government interventions caused a relatively high degree of spatial correlation and a multiple composite structure, i.e. Ind.-Res. and industrial-residential-commercial land-use structure (Ind.-Res.-Com.). However, the evolution characteristics of the composite structure in various regions illustrate some problems, such as the spatial isomorphism phenomenon of the composite structure and the dislocation of urban built-up land allocation. The urban internal built-up land spatial layout pattern is the embodiment of two dominant driving forces, the market and the government, interacting with each other according to natural and socioeconomic conditions. Therefore, we suggest that it is necessary to reform the future urban built-up land granting mechanism based on market guidance, and the composite structure of UBLS should be adjusted according to the regional function. The government should reinforce the macro-control of land-use planning for the dispersed granted land parcels so as to optimize the urban land-use structure.     

Searching for empirical linkages between demographic structure and economic growth

Demographic structure could affect economic growth through many channels. However, little is known about how demographic structure affects economic growth since no study has examined an extensive collection of channels through which demographic structure could affect economic growth in a single context. This paper overcomes this limitation by examining 45 potential mediating variables between demographic structure and economic growth. A causal search algorithm is used to identify channels through which demographic structure affects economic growth. Our results suggest that demographic structure affects economic growth differently between developed and developing countries. For developed countries, we find that an increase in the share of middle-aged workers has a positive effect on economic growth through institutions, investment and education channels. On the other hand, an increase in the share of the senior population has a negative effect on economic growth through institutions and investment channels. For developing countries, we find (but with weak evidence) that an increase in the share of young workers has a negative effect on economic growth through investment, financial market development and trade channels.