公路建设中路线方案多属性决策方法的研究

路线方案的比选是公路建设项目前期的一项重要工作,直接影响着项目建设能否达到预期的目标以及项目投入运营中的使用效果,如行车的安全性、舒适性、快捷性等。进行路线方案比选时,要考虑路线的线形合理性、对周边地区环境影响,项目经济效益、施工难易等多种因素对影响。本文在分析路线方案比选复杂性的基础上,对多种决策方法进行对比,选择TOPSIS法作为路线方案的决策方法。算例的结果表明该方法应用的可行性和有效性。     

Efficient Liability Rules: Complete Characterization

Received May, 18, 2000; revised version received March, 19, 2001     

PROCYCLICAL RETAIL LABOUR PRODUCTIVITY*

The influence of lagged adjustment and consumer spending on retail labour productivity is investigated. Both influences result in a procyclical productivity pattern.     

金融资产管理公司诉讼案件的法律思考

金融资产管理公司处置不良资产诉讼中仍面临许多法律问题,较为突出的有诉讼主体资格问题、诉讼管辖问题、诉讼时效问题、担保效力问题、撤销权问题,资产管理公司应充分利用法律法规和关于资产管理公司诉讼的司法解释,采取相应的法律对策,有效地通过诉讼实现资产保全.     

Time Series Concepts for Conditional Distributions*

The paper asks the question – as time series analysis moves from consideration of conditional mean values and variances to unconditional distributions, do some of the familiar concepts devised for the first two moments continue to be helpful in the more general area? Most seem to generalize fairly easy, such as the concepts of breaks, seasonality, trends and regime switching. Forecasting is more difficult, as forecasts become distributions, as do forecast errors. Persistence can be defined and also common factors by using the idea of a copula. Aggregation is more difficult but causality and controllability can be defined. The study of the time series of quantiles becomes more relevant.     

Demographic and Economic Pressure on Emigration out of Africa*

Two of the main forces driving European emigration in the late nineteenth century were real wage gaps between sending and receiving regions and demographic booms in the low‐wage sending regions. Our new estimates of net migration for the countries of sub‐Saharan Africa show that exactly the same forces driving African across‐border migration are at work today. The results suggest that rapid growth in the cohort of potential young emigrants, population pressure on the resource base, and slow economic growth are likely to intensify the pressure for migration out of Africa and into high‐wage OECD countries over the next two decades.