Random coefficients models of arms imports

This paper uses a large panel of data with up to 19 time-series observations for almost 150 countries to estimate models of arms imports. Qualitative evidence suggests a non-linear relationship. As income and military expenditure grow, the propensity to import first rises and then falls as a domestic arms industry develops. We face the difficulty that there is virtually no data on domestic arms procurement or production capability. We respond to this difficulty by adopting a random coefficient approach in order to identify any systematic influences on import propensity, through the impact of military expenditure, size of the armed forces or income on unobserved domestic production capability. While a clear non-linear pattern is apparent in the cross-section relationship, once one allows for parameter heterogeneity such a pattern is not apparent in the time-series.     

CHH际资本流入的贸易增长效应分析

以汇率和经济增长作为国际短期资本影响国际贸易的中间变量,采用Eviews6．0,从总体上考察国际资本流入对我国进出口的影响。从模型得出,随着FDI的增加,我国的出口额会增加,进口额会减少,而短期内FDI的增加对我国的进出口都起着促进作用;人民币实际有效汇率的贬值无论在长期和短期都对出口起着促进作用,对进口起着抑制作用。因此,在国际资本大量流入的情况下,只有积极吸引FDI,有效防范短期资本大幅度波动,才能保持贸易收支的相对稳定。     

双边间接网络效应对平台产品扩散与定价的作用研究

本文在BASS扩散模型的基础上,引入双边间接网络效应的作用,建立平台产品的扩散模型。研究发现:双边间接网络效应产生潜在的市场规模扩张,其和市场单边自扩散共同作用,使得平台产品的扩散形态可能呈单峰或多峰形状。按双边扩散表现为相互制约还是相互促进,平台产品市场扩散可分为潜在市场规模扩张起飞前和潜在市场规模扩张起飞后两个阶段。平台运营者需要正确判断产品扩散所处的阶段,谨慎制定正确的定价策略。     

户外休闲坐具设计影响因素与设计原则研究

户外休闲坐具不仅是城市居民休闲生活的主要用具,也是城市公共设施的重要构成元素。目前城市户外休闲坐具存在数量不够、设计不符合人体工程学、坐具设计与设置忽视人的行为与心理等问题,根据＂人-机-环境＂的系统观,分析了户外休闲坐具设计受到休闲主体——人、休闲坐具本身以及休闲环境三个关联因素的影响,提出了户外休闲坐具设计应把握人性化、与公共环境协调、耐久性与安全性、功能性、系统性等六大设计原则。     

Do bookmakers possess superior skills to bettors in predicting outcomes?

In this paper we test the hypothesis that bookmakers display superior skills to bettors in predicting the outcome of sporting events by using matched data from traditional bookmaking and person-to-person exchanges. Employing a conditional logistic regression model on horse racing data from the UK we find that, in high liquidity betting markets, betting exchange odds have more predictive value than the corresponding bookmaker odds. To control for potential spillovers between the two markets, we repeat the analysis for cases where prices diverge significantly. Once again, exchange odds yield more valuable information concerning race outcomes than the bookmaker equivalents.     

Short Run Constraints and the Increasing Marginal Value of Time in Recreation

Leisure activities such as local recreation trips usually take place in discrete blocks of time that are surrounded by time devoted to other commitments. It can be costly to transfer time between blocks to allow for longer outings. These observations affect the value of time within those blocks and suggest that traditional methods for valuing time using labor markets miss important considerations. This paper presents a new model for time valuation that uses non-employment time commitments to infer the shadow value of time spent in recreation. A unique survey that elicited revealed and stated preference data on household time allocation is used to implement the model. The results support the conclusion that there is an increasing marginal value of time for recreation as the trip length increases.     

Speculative dynamics

We develop a method for solving for equilibrium outcomes in stationary strategic settings in which speculators are informationally large and understand how their actions affect the information content of prices. This allows us to characterize speculation by institutional investors who receive private long-lived information on a recurring basis, and trade strategically. When the underlying asset value process has a stationary autoregressive structure, we develop a contraction mapping argument to solve for the stationary linear equilibrium. We derive analytically and numerically how the characteristics of private information—its quantity, persistence and correlation, and division among speculators—affect trading profits, pricing and trading strategies. Our central finding is that what matters for equilibrium outcomes are the most recent signals that speculators receive. Speculators trade so much more aggressively on new information than old that the bulk of their profits come from their two or three most recent private signals. Trading on past prices drops off faster yet; effectively only the most recent price matters.     

Quantitative growth effects of subsidies in a search theoretic R&D model

Should government subsidize R&D and does it matter how these subsidies are allocated? We examine these questions in a dynamic model where R&D is described as sequential sampling from a distribution of new ideas. Successful discoveries affect future available resources and incentives for further R&D. Consequently, there may be under-investment in R&D. We study the effect of government interventions aimed at fostering growth through R&D. Calibrating the model with aggregate data from the Israeli business sector allows us to quantitatively compare two forms of support resembling those actually used to encourage R&D in the Israeli business sector: (i) an unrestricted subsidy that may be used at the recipients' discretion to finance R&D or other investments, (ii) a subsidy earmarked by the government for R&D activities only. While there is no theoretical way to determine which of the two subsidies will have a greater impact on search for new ideas and growth, we find that in the calibrated economy both subsidies have a significant but similar impact on the economy's output and TFP growth rates. Accordingly, in the case of the Israeli business sector, the incentives to conduct R&D were sufficiently strong, and no R&D-specific encouragement was needed. However, a sensitivity analysis reveals that for economies characterized by other parameter values this result may not be true. Correspondence to: B. Bental     

高职学生网络学习动机探究

通过阐述学习动机在高职学生进行网络课程中的作用,并在分析当前网络课程中学习动机激发存在的几点问题的基础上,着重探讨了高职学生网络课程学习中激发和保持学习动机的策略,从而促进数字化学习的开展。     

基于技术进步的中国能源回弹效应研究

采用中国大陆地区30个省、直辖市、自治区(除西藏外)1995—2014年面板数据,测算各省空间相关性的技术进步贡献率.运用LMDI方法将能源强度分解为技术进步和产业结构效应,从能源回弹效应的定义及机理出发,研究中国能源回弹效应现象.结果表明:中国1996—2014年回弹效应的发展趋势可以分为三个阶段:部分回弹效应阶段(1996—1999年)、逆反效应阶段(2000—2008年)、部分回弹效应阶段(2008—2014年);整体来说,中国能源回弹效应平均值为64.77%,处于部分回弹阶段,表明达到一定的节能的效果,但仍有较大的提升空间;可以通过技术革新,优化结构来提高节能效率.