三维GIS在“数字长沙”中的应用实例

文章就三维GIS在“数字长沙”中的应用进行了探讨,阐述了利用三维GIS为长沙市政府区域建立三维全信息模型的结构、主要功能及应用。     

技术标准——企业协作研发的新动力

通过对以往协作研发的动力的回顾,作者提出了技术标准是企业协作的新动力,并用理论与实证的方法进行了论证。     

跨国公司国际研发的新趋势与发展中国家的对策

跨国公司作为全球经济的发动机，依然是国际研发的主体。但是，随着经济全球化的不断深入发展，跨国公司的国际研发也出现了新的发展趋势，跨国公司在发展中国家的研发投入日益增加，给发展中国家带来了机遇和挑战。本文认为，发展中国家在积极吸引跨国公司研发投资的同时，应该趋利避害，发展本国的经济。     

Calculating a Standard Error for the Gini Coefficient: Some Further Results*

Several authors have suggested using the jackknife technique to approximate a standard error for the Gini coefficient. It has also been shown that the Gini measure can be obtained simply from an artificial ordinary least square (OLS) regression based on the data and their ranks. We show that obtaining an exact analytical expression for the standard error is actually a trivial matter. Further, by extending the regression framework to one involving seemingly unrelated regressions (SUR), several interesting hypotheses regarding the sensitivity of the Gini coefficient to changes in the data are readily tested in a formal manner.     

Firm Density and Industry R & D Intensity: Theory and Evidence

By deriving a formal model of industry R & D that identifies factors influencing industry R & D intensity, this paper first suggests firm density, defined as the inverse of average firm sales or simply the number of firms divided by industry sales, as a measure of market structure that is appropriate in explaining industry R & D intensity. The model shows that the cost structure of R & D, consumer preference over quality and price, the appropriability of R & D, firm density, and the average level of firm R & D intensity jointly determine industry R & D intensity. In particular, firm density has a positive relationship with industry R & D intensity, implying that firms in higher firm-density industries feel fiercer competitive pressure and thus engage more intensively in R & D. An empirical analysis of panel data on industry R & D activities of Korean manufacturing industries during the period 1991–1996 provides supportive evidence for the predictions of the model including the positive relationship between firm density and industry R & D intensity. The theoretical model and the empirical results are also consistent with the recent survey of U.S. corporate R & D activities by the U.S. Department of Commerce and the National Science Foundation (1999).     

Risk compensation in wages – a replication

We use data from Germany, The Netherlands, Portugal and Spain to test for the effect of earnings variation on individual earnings. We replicate estimates for the USA and find that the variance of earnings in an occupation affects individual wages positively while the skewness of earnings has a negative effect. Both results are in conformity with wage compensation for risk averse workers. First version received: March 2001/Final version received: July 2002 We are grateful to two anonymous referees for valuable comments.     

Income taxes, spending composition and long-run growth

The focus of this paper is threefold. First, it reexamines the impact on long-run growth of changes in flat-rate income taxes when a fraction of total government expenditures is used to provide public services that affect the productivity of privately held inputs. Second, for a given tax policy, this paper studies the impact of government expenditure composition on the rate of economic growth. Third, since demographics follow an overlapping generations structure and fiscal policy affects the economy's productivity, the paper features the role of productivity as a means of redistributing income across generations. The economy is analyzed numerically and policy experiments are carried out.     

(Non-)existence and Scope of Nash Networks

For the connections model of strategic network formation, with two-way flow of information and without information decay, specific parameter configurations are given for which Nash networks do not exist. Moreover, existence and the scope of Nash network architectures are briefly discussed. We would like to thank two referees for helpful comments.     

Long persuasion games

This paper characterizes geometrically the sets of all Nash and perfect Bayesian equilibrium payoffs achievable with unmediated communication in persuasion games, i.e., games with an informed expert and an uninformed decisionmaker in which the expert's information is certifiable. The first equilibrium characterization is provided for unilateral persuasion games, and the second for multistage, bilateral persuasion games. As in Aumann and Hart [R.J. Aumann, S. Hart, Long cheap talk, Econometrica 71 (6) (2003) 1619-1660], we use the concepts of diconvexification and dimartingale. A leading example illustrates both geometric characterizations and shows how the expert, whatever his type, can increase his equilibrium payoff compared to all equilibria of the unilateral persuasion game by delaying information certification.