Public and Private Learning from Prices, Strategic Substitutability and Complementarity, and Equilibrium Multiplicity

We study a general static noisy rational expectations model, where investors have private information about asset payoffs, with common and private components, and about their own exposure to an aggregate risk factor, and derive conditions for existence and uniqueness (or multiplicity) of equilibria. We find that a main driver of the characterization of equilibria is whether the actions of investors are strategic substitutes or complements. This latter property in turn is driven by the strength of a private learning channel from prices, arising from the multidimensional sources of asymmetric information, in relation to the usual public learning channel. When the private learning channel is strong (weak) in relation to the public we have strong (weak) strategic complementarity in actions and potentially multiple (unique) equilibria. The results enable a precise characterization of whether information acquisition decisions are strategic substitutes or complements. We find that the strategic substitutability in information acquisition result obtained in Grossman and Stiglitz (1980) is robust.rational expectations equilibrium, strategic complementarity, multiplicity of equilibria, asymmetric information, risk exposure, bedging, supply information

In Trusts We Trust: Pension Funds Between Social Protection and Financial Speculation.

les réformes européennes des retraites ont pris pour référence le système américain. cet article propose de comprendre les origines d'une telle croyance persistante dans les vertus des fonds de pension. l'analyse met en évidence le rôle joué par leur structure juridique, le trust, dans la légitimation de la "pension industry".Recent reforms of European pension schemes have largely taken the American system as a reference.The remarks which follow are aimed at understanding the origins of such a persistent belief in the virtues of the pension funds. The analysis brings out the role played by their legal structure, the trust, in the legitimisation of the ‘pension industryFonds de pension; Trust;

Global tax hubs

Global tax hubs are the black boxes of the international tax regime (ITR). The driving forces of their strategic interaction with other building blocks of the ITR remain undertheorized. This paper offers the first theory of tax hubs as a two-sided global marketplace. It argues that tax hubs are the matchmakers of the ITR. Indeed, international investors, tax hubs and endpoint jurisdictions play different yet interrelated roles within the same ecosystem, i.e., the two-sided platform. The theory is positive rather than normative. It aims to explain how the creeping marketization of the ITR, as part of international law, has been frequently instrumented worldwide over the last century. The paper provides a stress test to the theory’s explanatory power and its limitations. The conceptual framework of this piece rests on antitrust law and economic concepts

Essays on Social Media, Hiring Networks and Firm Performance

This dissertation includes three essays that examine the impact of information technology on organizational performance. In the first essay, we examine the impact of network structure in the hiring of IT versus non-IT labor on firm performance. We find that hiring IT workers from a structurally-diverse network of firms has a positive effect on firm productivity, while there is no similar effect for non-IT labor in general. We attribute this to the different nature of knowledge diffused through the two types of labor: IT labor enables the transfer of new and innovative firm practices which benefits from diversity, while non-IT labor flows are associated with implementation of organizational practices, which may benefit from hiring more employees with a common knowledge base. In the second essay, we examine the economic value of social media investments and identify the organizational complements. We argue that social media brings in large amounts of real-time data, requiring a sufficient amount of data analytical skills for organizations to effectively process the information and integrate it into organizational decision making. We find evidence that the value of social media investments is higher in firms with a larger pool of data analytic skills in the labor force. In addition, social media’s positive impact on firm performance extends beyond the marketing department, and is further increased when the data analytic skills are dispersed throughout the firm. In the third essay, we investigate whether startup firms’ use of social media is associated with increased success in raising venture capital. We find that an active social media presence and strong Twitter influence increase a startup’s chances of receiving more funding and from a larger pool of investors. Specifically, social media improves startup funding success through two channels: reducing the search cost for investors to discover new investment opportunities and providing an additional channel of information for investors to better evaluate startup quality

Link formation in mobile and economic networks : model and empirical analysis

In this dissertation, we study three link formation problems in mobile and economic networks: (i) company matching for mergers and acquisitions (M&A) network in the high-technology (high-tech) industry, (ii) mobile application (app) matching for cross promotion network in mobile app markets, and (iii) online friendship formation in mobile social networks. Each problem can be modeled as link formation problem in a graph, where nodes represent independent entities (e.g., companies, apps, users) and edges represent interactions (e.g., transactions, promotions, friendships) among the nodes. First, we propose a new data-analytic approach to measure firms' dyadic business proximity to analyze M&A network in the high-tech industry. Specifically, our method analyzes the unstructured texts that describe firms' businesses using latent Dirichlet allocation (LDA) topic modeling, and constructs a novel business proximity measure based on the output. Using CrunchBase data including 24,382 high-tech companies and 1,689 M&A transactions, we empirically validate our business proximity measure in the context of industry intelligence and show the measure's effectiveness in an application of M&A network analysis. Based on the research, we build a cloud-based information system to facilitate competitive intelligence on the high-tech industry. Second, we analyze mobile app matching for cross promotion network in mobile app markets. Cross promotion (CP) is a new app promotion framework, in which a mobile app is promoted to the users of another app. Using IGAWorks data covering 1,011 CP campaigns, 325 apps, and 301,183 users, we evaluate the effectiveness of CP campaigns in comparison with existing ad channels such as mobile display ads. While CP campaigns, on average, are still suboptimal as compared with display ads, we find evidence that a careful matching of mobile apps can significantly improve the effectiveness of CP campaigns. Our empirical results show that app similarity, measured by LDA from apps' text descriptions, is a significant factor that increases the user engagement in CP campaigns. With this observation, we propose an app matching mechanism for the CP network to improve the ad effectiveness. Third, we study friendship network formation in a location-based social network. We build a structural model of social link creation that incorporates individual characteristics and pairwise user similarities. Specifically, we define four user proximity measures from biography, geography, mobility, and short messages (i.e., tweets). To construct proximity from unstructured text information, we build LDA topic models of user biography texts and tweets. Using Gowalla data with 385,306 users, three million locations, and 35 million check-in records, we empirically estimate the structural model to find evidence on the homophily effect in network formation.Computer Science

The Digital Divide: Current and Future Research Directions

The digital divide refers to the separation between those who have access to digital information and communications technology (ICT) and those who do not. Many believe that universal access to ICT would bring about a global community of interaction, commerce, and learning resulting in higher standards of living and improved social welfare. However, the digital divide threatens this outcome, leading many public policy makers to debate the best way to bridge the divide. Much of the research on the digital divide focuses on first order effects regarding who has access to the technology, but some work addresses the second order effects of inequality in the ability to use the technology among those who do have access. In this paper, we examine both first and second order effects of the digital divide at three levels of analysis ? the individual level, the organizational level, and the global level. At each level, we survey the existing research noting the theoretical perspective taken in the work, the research methodology employed, and the key results that were obtained. We then suggest a series of research questions at each level of analysis to guide researchers seeking to further examine the digital divide and how it impacts citizens, managers, and economies

Specialization in the Presence of Trade and Financial Integration: Explorations of the Integration-Specialization Nexus

In this paper we investigate the economic integration - industrial specialization nexus and unravel the relationship between trade and financial openness and industrial specialization. For a panel of 31 countries over the period 1970 to 2005, we find that trade integration relates negatively to specialization, while financial integration relates positively tospecialization. Furthermore, the relationship between trade (financial) integration and specialization is further deepened by the level of financial (trade) integration. Lastly, trade integration has a stronger connection to industrial specialization in countries with a high degree of intra-industry trade, whereas financial integration has a stronger connectionto specialization in countries with a relatively underdeveloped financial system. Our findings are robust to various measures and alternative model specifications.financial economics and financial management ;

Implications of Social Networks on Medication Information- Seeking Among Middle Eastern International Students: An Exploratory Study

The study examined how international students use their social networks to seek medication information, how their social networks provide social support, and how perceived social support is related to seeking medication information online. While there has been a paucity of research on the way international students seek information in their day-to-day lives (Sin and Kim, 2013), there is still a gap in the literature regarding how social networks employed by international students have a positive impact on building bridges toward home. In particular, no studies on the use of social support in social networks to retrieve medication information exist. This study aims to investigate whether social networking can serve as an effective channel for medication-related social support (MRSS) among Middle Eastern international students in the United States. In addition, this study investigates the factors affecting the intentions of students’ medication information-seeking behaviors within social networks, including the relationships between perceived social support, health consciousness, perceived barriers during the search for medication information, and the act of seeking medication information online. Data analysis employed a convergent mixed method design and Structural Equation Modelling techniques. This study is framed by two theoretical perspectives– (1) Chatman\u27s Information Poverty Theory (1996) and (2) Media Complementarity Theory (Dutta-Bergman, 2004a). Of the 208 Omani, Saudi, and Iraqi students attending the University of South Carolina, Columbia campus, 187 students completed the survey. The findings indicated that important sources of medication information in social networks for the students were their family members, relatives or friends who are medical professionals. In summary, the results reveal how a high level of health consciousness, as well as a relatively high number of perceived barriers when searching for medication information by conventional means, encouraged the students to utilize social networks more and seek social support. Increased social support leads to greater perception of emotional and esteem support thereby facilitating verification and validation of information attained through social networks. This social support can indeed benefit international students by enhancing their confidence in managing their medication information seeking

Ethics and taxation : a cross-national comparison of UK and Turkish firms

This paper investigates responses to tax related ethical issues facing busines