Contagion effects of national innovative capacity: Comparing structural equivalence and cohesion models

The effective promotion of national innovation performance is a crucial component of national innovation policy. This study examines network contagion effects of national innovative capacity via the international diffusion of embodied and disembodied technology by two different social network models: the cohesion model, based on diffusion by direct communication, and the structural equivalence model, based on diffusion by network position similarity. This investigation then utilizes data of 42 countries during 1997 to 2002 to empirically examine their network relationship. The analytical results demonstrate that international technology diffusion influences national innovation performance through contagion effects, but that the international similarity of national innovative capacity performance is more accurately predicted by network position than by interactions with others; and this study result provides a new perspective for science and technology policy makers.     

Control and spread of contagion in networks with global effects

We study proliferation of an action in binary action network coordination games that are generalized to include global effects. This captures important aspects of proliferation of a particular action or narrative in online social networks, providing a basis to understand their impact on societal outcomes. Our model naturally captures complementarities among starting sets, network resilience, and global effects, and highlights interdependence in channels through which contagion spreads. We present new, natural, computationally tractable, and efficient algorithms to define and compute equilibrium objects that facilitate the general study of contagion in networks and prove their theoretical properties. Our algorithms are easy to implement and help to quantify relationships previously inaccessible due to computational intractability. Using these algorithms, we study the spread of contagion in scale-free networks with 1000 players using millions of Monte Carlo simulations. Our analysis provides quantitative and qualitative insight into the design of policies to control or spread contagion in networks. The scope of application is enlarged given the many other situations across different fields that may be modeled using this framework.     

社会化网络环境下关键用户识别与产品知识扩散研究

随着社会化商务时代的到来,越来越多的商家意识到消费者网络对产品扩散的重要性,消费者网络节点重要性评价成为营销领域研究的重要内容。传统社会网络节点评价方法考虑了网络的局部拓扑结构,忽略了节点间的相互影响,PageRank考虑了来自邻居的影响力但忽视了节点间本身的重要性。提出了将社会网络中心性与PageRank方法相结合的消费者网络节点价值评价指标构建方法,基于现实数据构建了消费者网络,通过相似性算法对评价算法进行了讨论,运用SIS模型研究了不同节点的产品知识扩散效果,发现网络节点重要性与产品知识扩散显著相关,WCR算法优于传统中心性指标。     

Modeling,analysis and mitigation of contagion in financial systems

Recent financial turmoil (e.g., the 2008–2009 global financial crisis) has resulted in financial contagion-induced instability becoming one of the major concerns in the fields of economics and finance. In this paper, we extend the network analysis of financial contagion from three perspectives. First, given that cross-holding of claims and obligations among financial institutions can be viewed as input-output linkages, we model the financial system and the contagion mechanism by introducing the classic Leontief input–output framework. Second, based on this modeling process, we propose a simple contagion algorithm to study how financial system heterogeneity influences its stability. Third, to mitigate financial contagion, we propose several concrete intervention policies based on two widely used prudential approaches—forced mergers and capital injections. The performance of these intervention policies is then evaluated by comprehensive numerical experiments. Our study has significant implications for financial regulation and supervision.     

基于D-D模型的退保风险传染效应研究

The prevention and control of financial risk has been placed at a more prominent position at present. Preventing the risk of cross infection and systemic risk is one of the most important tasks of the current insurance industry. The crisis signal of an insurance company may shake the confidence of consumers to a large extent, leading to a “flock effect” that causes the risk spillovers and make the insured surrender or no longer renew, which could eventually lead to systemic risk. In this paper, based on a micro perspective and D-D model, we take the insurance companies different levels of loss claims as a key variable to establish a closed insurance market model, to study the relationship between the surrender behavior and the risk contagion, and carries on the numerical simulation and the sensitivity analysis to the risk infectivity caused by the insured under different crises. The study found that there is a critical jump point when the insured faces a different degree of crisis in the insurance company, and the behavior of the insured has a certain degree of influence on the systemic risk transmission. The regulatory authorities and insurance companies need to pay attention to the contagion effects of systemic risk caused by expectations and behaviors of policyholders.     

First-best health policy in vaccine markets with health and network externalities

This paper considers an oligopolistic market for a vaccine, characterized by negative network effects, which stem from the free-riding behavior of individuals engaged in a vaccination game. Vaccine markets often suffer from three imperfections: high concentration, network effects, and a health externality (contagion). The first conclusion of the paper is that the negative network externality is important as a market distortion, as it may lead to significant welfare losses. The second and main part of the paper develops a two-part per-unit subsidy scheme that a social planner could use to target both consumers and producers of vaccines. The scope of such a subsidy scheme to induce the firms to produce the first-best output without network effects (which is the most ambitious first-best target) is investigated. In many cases, while the first-best is attainable, it requires negative prices for vaccines, which amounts to rewarding consumers to induce them to vaccinate.     

The relationship between innovation network and innovation capability: a social network perspective

The key for acquiring innovation capability is knowledge transmission which is primarily based on the closer and tighter connections among businesses and other actors within innovation networks. Previous literature of patent analysis based on social network only explains the most influential corporations within an industry through social network indicators, but did not investigate the impact of these indicators on a firm’s innovation capability. This study uses social network perspective ‘centrality, cohesion and density’ to investigate the relationship between innovation network and innovation capability in the global semiconductor industry. Two purposes of this study are: (1) to investigate the innovation network relationship within the semiconductor industry at different periods and its evolution and (2) to study whether network position occupied by a firm in innovation network influences innovation capability. The empirical results show that firms with higher centrality and higher density have stronger innovation capability, but the weaker innovation capability with closer connection of sub-cluster (cohesion).     

Contagion and competitive effects of plan confirmation of reorganization filings: Evidence from the Taiwan Stock Market

This paper aims to examine the intra-industry effects of confirmation of a reorganization plan. Using unique Taiwanese data on announcements of reorganization confirmation, I find evidence that such announcements elicit positive stock price reactions for the announcing firms and negative stock price reactions for other firms within the same industry. Specifically, negative competitive effects dominate positive contagion effects for industry rivals in the context of the announcement of a reorganization confirmation. Moreover, a hybrid neuro-fuzzy model is constructed, where five industry- and firm-level inputs are considered, to investigate which rivals enhance their position and which do not. Results show that my model is consistent and stable, and is good at classifying both contagion- and competitive-effect candidates.     

The role of social support on relationship quality and social commerce

Empowered by social media, individuals are active content creators in social networking sites. This has brought new changes in business environment, of which social commerce is one of them. Social commerce, a new stream in e-commerce, highlights the role of technological advancements to develop a new social commerce era. In social commerce era, individuals share their knowledge, experiences, and information about the products and services with peers, providing a supportive environment in an online context. Drawn from social support theory, relationship quality, and social media concept this research proposes a model to investigate the role of social factors that impact on relationship quality and social commerce intention. A survey conducted on Facebook, a popular social networking site, and PLS-SEM method was applied to empirically test the proposed model. The results offer a valuable picture of social factors that influence relationship quality and social commerce intention. Towards these ends, the study highlights a new picture of consumers' behaviour in social commerce era. It provides a new theory in the area of research — social commerce. Practical implications of the research also highlight new technological changes in e-commerce platform and provide new strategies to firms to adopt these new technological advancements.     

基于位置大数据的中国跨境电商时空格局变化及其影响机制

以Wish平台注册商户位置大数据为主要数据源,综合运用DBSCAN聚类等地理可视化方法和面板回归模型分析方法,探究了2014—2018年我国大陆地区跨境电商时空格局变化及其影响机制。结果表明,该时段内跨境电商注册数量先增后降,形成了以北京、郑州、上海、义乌、长沙、成都、泉州、深圳为聚集中心的8个聚集区,而且"核心—边缘"分布特征明显。国内经济规模积累、知识经济与技术扩散、产业结构优化有助于跨境电商数量增长。片面追求外向型经济和服务型经济增长不利于跨境电商的发展。总体来看,我国跨境电商发展已进入经济高质量驱动阶段。文章提出了构建国内国际双循环相互促进跨境电商发展政策建议。     

Real estate prices and systemic banking crises

The collapse of real estate prices has historically jeopardized banking stability and triggered systemic banking crises. This paper studies risk contagion in a banking system in real estate price shock by adopting complex network theory. Modelling the real estate-related asset as a common exposure of banks to the real estate market, we propose a model that incorporates two main risk contagion channels, i.e., the financial network and asset fire sales, and reveal how the real estate price shock is transmitted and propagated across banks. We demonstrate that banking stability is highly sensitive to the real estate price shock. Moreover, due to the particularly low liquidity of the real estate market, the asset fire-sales of real estate assets overwhelms the financial network, playing the dominant role in risk contagion. Our model can be adopted by regulators to conduct stress testing and to forge effective risk management strategies.     

中国银行业系统性风险研究*——宏观审慎视角下的三个压力测试

本文在传统网络模型中加入去杠杆—降价抛售机制,研究以下两类宏观经济冲击对银行体系系统性风险的影响。从房地产贷款违约压力测试看,房地产贷款违约引起的传染风险是系统性风险的重要来源;传染损失比重和去杠杆次数结果则表明,2007年我国银行面临的传染风险最高,之后呈现快速下降的趋势;参数敏感性结果表明,网络模型中去杠杆、降价抛售以及破产对传染风险的相对重要性依次递减。从地方政府融资平台贷款违约压力测试看,大型商业银行受平台贷款违约的影响小于股份制和城市商业银行。此外,平台贷款违约概率存在阈值,在阈值之上银行损失和倒闭急剧攀升。基于银行倒闭压力测试,量化出本文的网络模型相对于传统网络模型的优越性。本文还发现中国金融体系的系统重要性与系统脆弱性指标的“错配”对于维持金融体系稳定非常关键。     

Tree networks to assess financial contagion

We propose a two-layered tree network model that decomposes financial contagion into a global component, composed of inter-country contagion effects, and a local component, made up of inter-institutional contagion channels. The model is effectively applied to a database containing time series of daily CDS spreads of major European financial institutions (banks and insurance companies), and reveals the importance of monitoring both channels to assess financial contagion. Our empirical application reveals evidence of a high inter-country and inter-institutional vulnerability at the onset of the global financial crisis in 2008 and during the sovereign crisis in 2011. The results identify France as central to the inter-country contagion in the Euro area during the financial crisis, while Italy dominates during the sovereign crisis. The application of the model to detect contagion between sectors of the European economy reveals similar findings, and identifies the manufacturing sector as the most central, while, at the company level, financial institutions dominate during the 2008 crisis.     

考虑影响不对称性的创新扩散与网络结构协同演化建模：基于信息熵与累积优势的仿真研究

创新扩散发生于社会系统中并通常与社会系统存在交互作用。网络是体现社会系统的重要手段，但已有研究中的扩散网络多为无向网络且具有静态或外生动态性质，上述处理方式忽视或无法体现扩散与以网络形式出现的社会系统的协同演化以及个体间的不对称影响。基于有向网络，提出能够体现创新扩散与网络协同演化的描述性框架，从信息搜寻与降低认知失调视角出发，基于信息熵与累积优势机制，在个体层面构造网络演化与创新采纳数学模型。在RepastSimphony2.7开发平台下，利用基于Java的智能体建模方法展开系统仿真实验。基于实验数据的描述性结果揭示，动态网络与静态网络下的创新扩散存在显著不同，网络结构演化将强化节点出度的不均衡状况，更优的扩散结果往往与更不均衡的节点出度分布同时出现，其它因素包括大众传播与人际传播等也会影响扩散与网络的协同演化；交互作用存在于控制变量间。推断性结果确认了控制变量影响与交互作用的普遍存在。     

Regime switches under policy uncertainty in monetary unions

This paper analyzes the effects of policy uncertainty on the stability of a monetary union. Focusing on peripheral countries, we study how uncertainty over the consequences of a possible exit affects regime switches. Applying game theory and a cost-benefit analysis, we model a regime switch as the endogenous result of a two-stage policy game. We find that the effects of uncertainty are not trivial. Unilateral exits are less probable, but contagion is more likely to be observed. Our results are driven by two opposite forces: a traditional conservative effect induced by policy uncertainty in a single policymaker framework, which calls for more stability, and a strategic effect, arising from the strategic interaction, which may undermine the monetary union's foundation and strengthen incentives for contagion.     

小世界网络下用户创新扩散效果分析

本文对用户创新的概念及相关研究成果进行了阐述,分析了用户创新扩散的特性;运用WS小世界网络模型构建了用户创新扩散的网络模型,并对扩散效果进行了模拟分析。结果表明:用户创新扩散在不同的网络结构下呈现出不同的结果;创新采纳比例在小世界区间达到最大;随着网络随机化程度的加大,平均创新知识水平变得更高,知识的均匀扩散能够更快实现。最后进行了案例分析。     

Using cellular automata to simulate electronic commerce receptivity in small organisations

The focus of the research is to study the dynamics of electronic commerce propagation caused by organisational characteristics in small organisations. A model of opinion dynamics and verbalisation process for studying the receptivity of electronic commerce in small organisations in Slovenia is proposed. The methodology is based on cellular automata approach, diffusion theory, small organisations characteristics and studies on factors affecting electronic commerce introduction and usage in small organisations. The decision of an organisation whether to adopt electronic commerce or not is based on its attitude towards electronic commerce and impressions gathered from interactions with other organisations. Different characteristics of organisations were defined according to the data gathered by interviews and a survey. Several types of electronic commerce diffusion dynamics are evident from the data gathered. The most likely scenario of electronic commerce diffusion among small organizations in Slovenia predicts a decrease in organizations that are less mature in e-commerce and the increase in more mature organizations by 6-8% by the end of year 2006.     

“一带一路”战略下中部六省专利实施许可网络研究

“一带一路”战略为中部地区科技创新成果转化提供了新机遇。为制定和优化中部地区跨域技术扩散政策,运用社会网络分析方法,以2015年度国家知识产权局专利实施许可备案数据为样本,分析了专利许可整体网络、跨区域专利许可网络、四大国家级自主创新示范区节点城市专利许可网络结构特征和技术类型。研究发现存在如下问题：中部六省在整体网络中处于次边缘层向次中心层过渡位置、地域结构与“一带一路”战略目标不匹配、自主创新示范区节点城市的技术扩散引领辐射作用不足。据此,提出了构建中部六省技术帮扶联盟增强科技扶贫力度、发挥区位优势搭建跨域技术扩散中介桥梁、优化示范区技术扩散评估和激励政策以及发挥技术比较优势等建议。     

危机事件的溢出效应:同质混合还是异质共存?——来自“3Q大战”的实证研究

文章以"3Q大战"为例,从竞争关系和社会距离两方面对危机事件的溢出效应进行了探讨,并首次证实了溢出效应具有异质性。具体而言,在竞争关系方面,竞争公司在危机事件中获得了正的累积超常收益而表现为竞争效应,而非竞争公司的累积超常收益则为负而表现为传染效应;在社会距离方面,距离最远的对立阵营在危机事件中获利,而中立阵营和联盟阵营则受损。文章不仅弥补了现有研究只关注混合的溢出效应的不足,也为未来深入探讨溢出效应的影响因素提供了经验证据。     

企业连锁董事网络中的社会资本不平等：基于先赋性与后致性因素的分析

社会资本在不同群体中分布不平等，但较少有研究分析精英群体中的社会资本不平等情况。基于陕西省上市公司2010-2017年数据，采用社会网络分析方法，分析不同性别（先赋性因素）和拥有不同教育背景（后致性因素）的董事在多项网络中心度上的差异。研究发现，网络中男性董事占据绝对数量优势，男女比例随时间变化呈稳定状态，但男性董事和女性董事在网络中心度上没有显著差异；受教育程度越高，董事越趋于网络中心地位。研究证实在董事群体中存在基于后致性因素的社会资本不平等，但不存在基于先赋性因素的社会资本不平等。