Global Networks of Trade and Bits

Considerable efforts have been made in recent years to produce detailed topologies of the Internet. Although Internet topology data have been brought to the attention of a wide and somewhat diverse audience of scholars, so far they have been overlooked by economists. In this paper, we suggest that such data could be effectively treated as a proxy to characterize the size of the "digital economy" at country level and outsourcing: thus, we analyse the topological structure of the network of trade in digital services (trade in bits) and compare it with that of the more traditional flow of manufactured goods across countries. To perform meaningful comparisons across networks with different characteristics, we define a stochastic benchmark for the number of connections among each country-pair, based on hypergeometric distribution. Original data are thus filtered by means of different thresholds, so that we only focus on the strongest links, i.e., statistically significant links. We find that trade in bits displays a sparser and less hierarchical network structure, which is more similar to trade in high-skill manufactured goods than total trade. Lastly, distance plays a more prominent role in shaping the network of international trade in physical goods than trade in digital services.Comment: 25 pages, 6 figure

Changing structures in transnational research networks: an analysis of the impact of COVID-19 on China's scientific collaborations

Research networks play pivotal roles in the creation and diffusion of knowledge. It is widely acknowledged that frontier research tends to cluster around transnational research networks (TRNs), which also represent strategic tools for nurturing innovation in R&D-intensive companies. Therefore, they are crucial for promoting the rapid development of the knowledge economy in underdeveloped countries. In this context, China's experience is particularly relevant because the country has invested heavily in knowledge production, which is arguably one of the most important structural changes at the global level in recent decades, with important implications for the division of labor and trade among countries. The country has been investing in order to become the scientific world leader, and in this transition, research collaboration, in particular with other countries, can become strategic. In this work, we analyze whether COVID-19 and related research have affected the shape of the network and the intensity of collaborations involving China in the field of health studies, comparing it to the case of the U.S. as the global leader in research (Fry et al., 2020). In particular, we wish to assess whether COVID-19-related research has pushed toward larger and more intensive collaborations internationally than before the pandemic or whether a tendency to closure has prevailed has prevailed. This also means understanding whether COVID-19, as a global phenomenon, has affected China in rising as an international research leader. To do so, we built an original dataset of international, coauthored publications involving China or the U.S. in selected health research fields. Our analysis first shows that COVID-19 research has assumed specific features distinct from other topics in the same research field, shaping research networks in a peculiar way for both China and the U.S. Second, for China, COVID-19 does not appear to have represented an opportunity to further climb up the international research ladder, as it has attracted a relatively low and more volatile number of collaborators from different countries

International financial integration : a complex network analysis

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Finansal entegrasyon yeni bir kavram olmadığı gibi küreselleşme de yeni bir fenomen değildir. Finansal entegrasyon; sınır ötesi sermaye hareketliliğindeki engellerin kaldırılması, deregülasyon politikaları, teknolojinin evrimi ve artan uluslararası işbirliği imkanları ile hız kazanmıştır. Yine de, dünya tamamen entegre olmaktan uzaktır ve artan sınır ötesi sermaye akışlarından gerçekten fayda sağlamayı başaran birkaç ülke vardır. Yapılan tez çalışması, uluslararası finansal ağın analiz tipolojisine ve evrimine ağ yaklaşımı ile ışık tutmaktadır. Ana veri kaynağı, IMF tarafından yayınlanan Eşgüdümlü Portföy Yatırım Anketi (CPIS) olup, 2004'ten 2015'e kadar olan dönemi kapsamaktadır. Analizde 70 ülkeye yer verilmiştir. Finansal ağ kalıplarını ve evrilmesini değerlendirmek için kullanılan ağ parametreleri: ağ yoğunluğu (network density), kümelenme katsayısı (clustering coefficient), düğüm merkeziliği (node centrality), aradalık merkeziliği (betweenness centrality), yakınlık merkeziliği (closeness centrality) ve merkezler ve otoriteler (hubs and authorities – HITS Algorithm). Bu tez çalışmasında, karmaşık bir ağ modeli kullanarak, finansal ağın haritasını çikarılması ve onun topolojisini ve emrimini analiz etmek amaçlanmaktadır. Bu tezin ampirik sonuçlarına göre, dış varlığı elinde bulunduran ülkeler artmaktadır, lakin en büyük portföy ($ cinsinden) ABD tarafından tutulmakta ve finansal ağdaki en etkili ülke olarak mutlak liderliğini sürdürmektedir. Japonya, İngiltere, Lüksemburg, Fransa ve Almanya da ağda oldukça etkili görünmektedir. Bu ülkeler büyük miktarda uluslararası çapta yayınlanmış finansal varlıklara sahiptir. Genel olarak, yapılan tez çalışmasının bulguları önceki çalışmaların sonuçları ile uyumludur. Finansal ağ merkez-çevre yapısıdır ve ağın merkezinde bulunan az sayıdaki ülke ve hem kendi arasında hem de geri kalan çevre ülkelerle finansal ilişkiler sürdürmektedir. Çevresel olarak sınıflandırılan ülkeler, merkez ülkelerle ilişkiler kurma eğilimindedir ve bu ülkelerin diğer ülkelerle bağlantı kurma konusunda daha az istekli oldukları görülmektedir.The concept of financial integration is not new and globalization itself is not a novel phenomenon. International financial integration was mainly accelerated due to removal of barriers on international capital flows, deregulation policies, technological evolution, increased international cooperation, etc. Still, the world is far from being fully integrated and international financial network clearly demonstrates a core-periphery structure. This thesis employs a network approach to explore typology and evolution of international financial network. Main data source is Coordinated Portfolio Investment Survey (CPIS) published by IMF and covers a period from 2004 until 2015. 70 countries are included in the analysis and sample is restricted due to data availability. Key network parameters used to assess financial web patterns and evolution are: network density, clustering coefficient, degree centrality, betweenness centrality, closeness centrality and hubs & authorities centrality. Applying a complex network analysis, main purpose of this thesis is to map and explain the typology and evolution of international financial integration. Empirical results of this thesis show that while there is an increasing number of countries holding geographically diversified portfolio of assets issued by non-residents, most influencing country in the financial network is the USA. Japan, UK, Luxembourg, France and Germany as well appear to be influential in the network owning large portfolios of internationally issued financial assets. In general, this thesis' findings are in line with previous studies considering financial network as a core-periphery structure, with a small number of countries located in the core of network and maintaining intensive relation both among each other and with the rest of network. On the other side, countries classified as periphery tend to establish relations with core countries and have less incentive to connect with other countries positioned in the periphery layer. Lastly, unlike expected, global and European financial crises did not significantly change position of countries in the international financial network

HYPERLINK NETWORK SYSTEM AND IMAGE OF GLOBAL CITIES: WEBPAGES AND THEIR CONTENTS

A distinctive trend of globalization research is a conceptual expansion that mirrors the penetration of globalization in various aspects of life. The World Wide Web has become the ultimate platform to create and disseminate information in this era of globalization. Although the importance of web-based information is widely acknowledged, the use of this information in global city research is not significant yet. Therefore, the purpose of this research is to extend the concept of globalization to the efficiency of information networks and the thematic dimensionality of the conveyed images from webpages. To this end, 264 global and globalizing cities are selected. The city hyperlink networks are constructed from the web crawling results of each city, and hyperlink network analysis measures the effectiveness of these hyperlink networks. The textual contents are also extracted from the crawled webpages, and the thematic dimensionality of the textual contents is measured by quantified content analysis and multidimensional scaling. The efficiency of the hyperlink network in information flow is confirmed to be a new consideration that shapes the globality of cities. The cities with high efficiency of connections have faster and easier access, which means better structure for city image formation. Specifically, social networking websites are the center of this information flow. This means that social interactions on the Web play a crucial role to form the images of cities. Apart from the positivity and the negativity of the city image, the dimensionality of cities on the thematic space denotes how they are expressed, discussed, and shared on the Web. The image status based on dimensions of globalization is an important starting point to city branding. It is concluded that a research framework handling information networks and images simultaneously deepens the understanding of how the structure and the contents on the Web affect the formation and maintenance of global city networks. Overall, this research demonstrates the usefulness of information networks and images of cities on the Web to overcome data inconsistency and scarcity in global city research

Computational Interdisciplinarity: A Study in the History of Science

abstract: This dissertation focuses on creating a pluralistic approach to understanding and measuring interdisciplinarity at various scales to further the study of the evolution of knowledge and innovation. Interdisciplinarity is considered an important research component and is closely linked to higher rates of innovation. If the goal is to create more innovative research, we must understand how interdisciplinarity operates. I begin by examining interdisciplinarity with a small scope, the research university. This study uses metadata to create co-authorship networks and examine how a change in university policies to increase interdisciplinarity can be successful. The New American University Initiative (NAUI) at Arizona State University (ASU) set forth the goal of making ASU a world hub for interdisciplinary research. This kind of interdisciplinarity is produced from a deliberate, engineered, reorganization of the individuals within the university and the knowledge they contain. By using a set of social network analysis measurements, I created an algorithm to measure the changes to the co-authorship networks that resulted from increased university support for interdisciplinary research. The second case study increases the scope of interdisciplinarity from individual universities to a single scientific discourse, the Anthropocene. The idea of the Anthropocene began as an idea about the need for a new geological epoch and underwent unsupervised interdisciplinary expansion due to climate change integrating itself into the core of the discourse. In contrast to the NAUI which was specifically engineered to increase interdisciplinarity, the I use keyword co-occurrence networks to measure how the Anthropocene discourse increases its interdisciplinarity through unsupervised expansion after climate change becomes a core keyword within the network and behaves as an anchor point for new disciplines to connect and join the discourse. The scope of interdisciplinarity increases again with the final case study about the field of evolutionary medicine. Evolutionary medicine is a case of engineered interdisciplinary integration between evolutionary biology and medicine. The primary goal of evolutionary medicine is to better understand "why we get sick" through the lens of evolutionary biology. This makes it an excellent candidate to understand large-scale interdisciplinarity. I show through multiple type of networks and metadata analyses that evolutionary medicine successfully integrates the concepts of evolutionary biology into medicine. By increasing our knowledge of interdisciplinarity at various scales and how it behaves in different initial conditions, we are better able to understand the elusive nature of innovation. Interdisciplinary can mean different things depending on how its defined. I show that a pluralistic approach to defining and measuring interdisciplinarity is not only appropriate but necessary if our goal is to increase interdisciplinarity, the frequency of innovations, and our understanding of the evolution of knowledge.Dissertation/ThesisDoctoral Dissertation Biology 201

The World Trade Web: A Multiple-Network Perspective

International Trade (IT) plays a fundamental role in today's economy: by connecting world countries production and consumption processes, it radically contributes in shaping their economy and development path. Although its evolving structure and determinants have been widely analyzed in the literature, much less has been done to understand its interplay with other complex phenomena. The aim of this work is, precisely in this direction, to study the relations of IT with International Migration (IM) and Foreign Direct Investments (FDI). In both cases the procedure used is to first approach the problem in a multiple-networks perspective and than deepen the analysis by using ad hoc econometrics techniques. With respect to IM, a general positive correlation with IT is highlighted and product categories for which this effect is stronger are identified and cross-checked with previous classifications. Next, employing spatial econometric techniques and proposing a new way to define country neighbors based on the most intense IM flows, direct/indirect network effects are studied and a stronger competitive effect of third country migrants is identified for a specific product class. In the case of FDI, first correlations between the two networks are identified, highlighting how they can be mostly explained by countries economic/demographic size and geographical distance. Then, using the Heckman selection model with a gravity equation, (non-linear) components arising from distance, position in the Global Supply Chain and presence of Regional Trade Agreements are studied. Finally, it is shown how IT and FDI correlation changes with sectors: they are complements in manufacturing, but substitutes in services.Comment: PhD thesis at IMT Institute for Advanced Studies Lucca. 114 pages, 12 figures, 18 table

Global Supply Chain Dynamics in the Mobile Handset Industry

The 21st century features disaggregated supply chains that can reduce costs but also limit firms’ ability to monitor and control critical processes, including labor practices and the sourcing of supplies. My dissertation examines issues of sustainability, accountability, and organizational structure in today’s world of globally dispersed supply chains. In particular, I empirically examine the evolution of buyer-supplier relationships in the mobile phone industry. The first empirical essay concerns how labor issues affect buyer−supplier relationships at the dyadic level. I examine the manner and mechanisms by which mobile phone companies respond to labor protests targeting their suppliers. I find that user-generated social media content can help make buyer-supplier relationship more visible to the public, pushing firms to disengage from protested suppliers. I also compare the consequences of labor protests, for which suppliers are partially responsible, to natural disasters, for which suppliers are not responsible. Furthermore, I conduct an exhaustive search of press releases and newspaper articles, and find that firms rarely acknowledge supply chain labor issues. This essay suggests that increasing the visibility of buyer−supplier links through user-generated social media can make firms more accountable for supply chain labor issues. The second empirical essay investigates how an industry-wide, sudden increase in the visibility of supply chains influences network mechanisms driving supply chain network evolution. I utilize stochastic actor-oriented models, specifying several events that occurred in 2010 as an environmental jolt. The findings indicate that the supply chain network became denser after the jolt, resulting in more opportunities for suppliers to attract new relationships. However, the level of network inequality also increased—previously popular suppliers captured most of the new opportunities. Thus, a previously dispersed and modularized network became more centralized, featuring a strong core-periphery structure. Firms’ endeavors to achieve supply chain sustainability in the aftermath of environmental jolts may allow established suppliers to remain entrenched as central players in the network. Overall, my dissertation underlines the importance of studying global supply chains to better understand industry evolution and corporate strategy in the 21st century. This work seeks to contribute to the research on organizational accountability, social movements, and social networks.PHDBusiness AdministrationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/140980/1/yonghyun_1.pdfDescription of yonghyun_1.pdf : Restricted to UM users only