A model of project evaluation with limited attention

Summary This paper characterizes the optimal policy for a model in which manager may adopt an endogenous number of projects but has only limited resources to devote to their evaluation and maintenance. In any period, the manager may discard any subset of existing projects but may evaluate only one existing or one new project which is then either discarded or restored. Both its current return and the probability with which a project may be restored depends only on the number of periods since its last evaluated. For a manager whose objective is to maximize the sum of discounted returns, the optimal policy takes one of two forms. A discard policy specifies that the manager evaluate a new project in each period and discard current projects at some critical age. An age inspection policy specifies that the manager evaluate a new project only if all current projects are sufficiently young.Support from the C. V. Starr Center for Applied Economics and the Research Resource Committee of the Rutgers Graduate School of Management is gratefully acknowledged. We thank Roy Radner for valuable assistance in the early stages of the work.     

Economic progress and skill obsolescence with network effects

Summary. We construct an OLG model with network effects to examine skill obsolescence when individuals can choose technological vintages. In the absence of transfer payments, some regions of the parameter space have unique stationary equilibria, others have unique cyclical equilibria, and others have multiple stationary equilibria. All equilibria are Pareto efficient. However, rat race equilibria can exist in which all agents currently alive prefer a slower rate of progress than occurs in equilibrium. When contemporaneous transfers are allowed, equilibria are unique everywhere, but a cycle still exists, and a rat race can still arise in equilibrium. Allowing intertemporal transfers (debt) ensures that all equilibria are stationary. In the relevant parameter range, the introduction of debt can eliminate cycles and increase the long-run growth rate. No rat race equilibria exist when debt is allowed.Received: 3 January 2002, Revised: 3 June 2004, JEL Classification Numbers: 041, J24, O33. Correspondence to: Ian P. KingEarly versions of this paper were presented at the West Coast Macro Workshop, the Mid-West Macro Meetings, the Canadian Macroeconomics Study Group Meetings, and the Society for Economic Dynamics Meetings. We would like to thank V. V. Chari, Merwan Engineer, Don Ferguson, John Hillas, John Knowles, Dan Peled, Dan Usher, Linda Welling and Julian Wright for helpful comments. We are especially grateful to an anonymous referee for some very useful and substantive comments.     

基于所有制性质的高技术企业创新能力差异及生成机理——源自省级面板数据的实证研究

构建基于改进突变级数法的评价模型，研究2009-2017年各省不同所有制高技术企业创新能力差异，采用ARCGIS软件进行可视化分析，运用全面FGLS回归模型探索不同所有制高技术企业创新能力差异生成机理。结果表明：①总体来看，内资企业与港澳台资和外资企业创新能力差距尚存；②省级层面不同所有制高技术企业创新能力呈现差异化状态，整体创新能力较强地区港澳台资和外资企业普遍强于内资企业，而其它地区则恰恰相反；③政府资助和引进高素质人才能够显著提升内资企业创新能力，加强产权保护、提高开放程度对内资、港澳台资和外资企业创新能力均具有积极作用。     

数字化技术作用下产品与服务创新：综述及展望

制造企业服务化过程中伴随着产品创新和服务创新，且两类创新协同演进是推动服务化进程的重要力量。当前，服务化研究大多以此为基点，探讨两类创新的关系，并且随着服务化的“数字化”特征越发明显，大多数学者从技术层面提出数字化技术对两类创新的促进作用。然而，鲜有学者考虑数字化技术对两类创新关系的影响，在一定程度上制约了数字服务化研究与实践。为此，首先通过系统回顾相关文献，分析两类创新的相互作用及其耦合困境；其次，厘清数字化技术促进两类创新的前因、过程与结果，并据此解析数字化技术增强两类创新耦合效应的作用机理；最后，提出该主题未来可拓展研究的三大方向。     

中欧贸易与欧盟技术性贸易壁垒

近年来,技术性贸易壁垒(TBT)已成为发达国家实施贸易保护主义更为隐蔽、更为有效的手段.作为中国第三大贸易伙伴的欧盟,其实施的各种TBT措施对中国的出口产品产生了严重的影响.因此,必须建立欧盟技术性贸易壁垒预警机制,时时监控其新动向;坚持"以质取胜"的原则,大搞技术创新和产品创新,以更高的产品质量标准和专利注册超越其贸易壁垒.     

汇率对产业内贸易的传导和冲击效应——基于中国东盟自由贸易区的分析

本文以中国与东盟六国18类产品的产业内贸易的月度面板数据作为分析基础，通过分析汇率与产业内贸易的传导关系、中国与东盟六国产业内贸易特点，并且建立产业内贸易指数与汇率的VAk模型．对我国的汇率对产业内贸易的冲击作用和动态关系做实证分析。研究发现：一是无论是短期或长期．汇率升值对绝大多数初级产品的产业内贸易是不利的，但在短期内它有助于提升大多数工业制品的产业内贸易水平．长期内对工业制品的产业内贸易冲击效应是分化的。二是汇率升值后长期内对不同劳动密集型产品的产业内贸易发展是一样的。三是无论是短期还是长期，初级产品的产业内贸易对汇率冲击的反应相当微弱．工业制品反应相对较强。     

地震勘探仪器技术及其发展

综合地震勘探整体的发展情况，比较细致的论述了地震勘探仪器当前应用的技术现状、基本发展规律、技术关键以及未来仪器技术的发展方向。     

对我国医药企业自主创新演化机制的分析

自主创新是当前商业界和学术界研究比较热的话题。政府相应地制定了一系列的政策和法规来鼓励企业进行自主创新。在这种背景下,我国的医药企业也积极响应国家的政策进行自主创新。然而,医药企业创新在实际操作中的行动方向差异很大。针对这种差异,笔者将医药企业创新划分成新功能创新和新设计创新两种,并且通过对一系列的数据和资料分析后,发现我国的医药企业的创新并非实质上的自主创新即新功能创新,而是新设计创新。文中对产生这种局面的演化机制进行了分析。     

Agglomeration in an innovative and differentiated industry with heterogeneous knowledge spillovers

This paper introduces an agent-based simulation model to study the technological development, the economic performance of firms and the evolution of agglomerations in a differentiated industry. The analysis is based on the interaction and behavior of firms, which might share knowledge but at the same time are competitors on the goods markets. Firms do not only compete with quantities they can also introduce process and product innovations. The level of knowledge of a firm describes the capabilities to perform innovations. Knowledge can be accumulated by investing in R&D and by knowledge spillover, which depend on geographical and technological proximity. Simulation runs show that there is an incentive to agglomerate in young industries and that geographical proximity enhances innovation, especially the number of product innovations.      

管理创新的"力场"分析

管理创新是在各种力的交互作用下产生的一种不规则性活动,只有当管理创新的动力大于阻力并取得支配地位时,管理创新行为才可能发生.管理创新的动力主要来源于需求拉力、竞争压力、利益内驱力、科技推力及政策激励力五个方面,而管理创新的阻力则主要来源于人的因素、组织的因素以及物质技术条件等.只有明确管理创新的"力场"构成,才能有目的地增强动力、克服阻力,实现增"正"减"负",从而推动管理创新活动的顺利进行.