Understanding Networks: Six degrees of finance, terrorism, movements, and sex

Spring 2010

General scope: The aim of this course is to give an overview of the key ideas of network science from a social science perspective. The concept of networks has come to pervade modern society, as we routinely make use of online social networking services, as business gets organized into network forms, and as warfare increasingly targets a loose network of combatants. Network science is an emerging interdisciplinary field, which aims at explaining such complex phenomena, emerging from simple principles of making links. Sociological research on the invisible network infrastructures of global finance, the emergence of social movements, or the formation and operation of terrorist groups all demonstrated that a few critical links can lead to dramatic transformations. This course gives an overview of key research findings in these areas, and it also introduces key methods to record, analyze, and visualize network data. Students will be given access to diverse datasets for class purposes.

Learning outcomes Students taking this course should be able to formulate a research project using concepts and methods from network science. Beyond an awareness of network studies in key sociological areas, students should also be able to apply network methods in their own research fields.

Course requirements and assessment Evaluation in the course is primarily based on a short research paper that is either based on datasets discussed in class, or small scale data collection by students. Beyond the research paper students should also prepare an in-class presentation, and participate in class discussions.

Basis of Evaluation:
Research paper: 70%
Class participation: 15%
Presentation: 15%

Course Structure Each meeting in the semester will feature theoretical pieces and applications along with a presentation of techniques informed by these. In each of the weeks datasets will be provided to try and test ideas discussed in the writings.

1. Introduction: networks all around… Networks became an important element of contemporary public consciousness. While it is next to impossible to parse out the extent to which our lives became more networked and the increase in the awareness of networks all around us - it is certain that the science of networks is coming of age. In this first meeting we discuss the key areas where this new science has something to say, using Barabasi's book as a guide.

Barabási, Albert-László. 2002. Linked: The New Science of Networks. Perseus Publishing. (ch 1-2)

Assignment: Use http://www.visualcomplexity.com. Choose your favorite case of visualization of the 708 projects featured in this gallery, and introduce it in a short presentation.

2. The strength of weak ties and the power of six degrees Social networks have a surprisingly short average path length - between any two inhabitants on Earth there is a path of at most six steps. This cohesion of social networks is created by weak ties that can be activated in social search. We discuss practical concepts (paths, path length, network diameter), and we use these concepts on various social networks.

Barabási, Albert-László. 2002. Linked: The New Science of Networks. Perseus Publishing. (ch 3-4)
Granovetter, M. 1973. "The strength of weak ties." American Journal of Sociology 81:1287-1303.
Watts, Duncan J. 1999. Small Worlds. Princeton University Press. (selection)

Assignment: use your account on any online social networking site (Facebook, LinkedIn, etc) and chart the network of your friends. Try to determine the number of steps your friends need to take to reach each other if you exclude yourself from this network.

Resources:
Use this application to download your own Facebook network (choose UCINET format).
Download Balazs' Facebook network
A link to Ronald Burt's website (with lots of papers, and questionnaires)
UCINET 6, general social network analysis software (for windows systems)

3. Power and centrality Networks are far from being a domain of equality. Contrary to techno-romanticist expectations about the internet, the distribution of attention on the Web is highly unequal. Networks of corporations are centered around dominant firms. Personal networks are centered around sociometric stars. We discuss measures of network centrality, and use the example of the World Wide Web to see how emergent inequalities shape its macrostructure.

Barabási, Albert-László. 2002. Linked: The New Science of Networks. Perseus Publishing. (ch 7)
Broder, Andrei, et al. 2000. "Graph structure in the Web." Computer Networks 33(1-6):309-320.
Barabasi, Albert-Laszlo et al. 2000. "Scale-free characteristics of random networks: the topology of the world-wide web." Physica A 281:69-70.

Assignment: Use the account provided in class for IssueCrawler, and map a network of websites of your interests. It is especially interesting if you try an area of supposed equality, like humanitarian aid, NGOs, education. Give an account of power inequalities. You can also use the blogosphere dataset.

Resources:
Download the political blogs dataset, and also the vector describing ideological affiliation (0=left, 1=right)
This is the original source of this data and here is a publication from those who collected the data.

Here is a link to IssueCrawler, a site that enables you to collect web hyperlink netowrk data. Email me for login and password.

Download the financial firm dataset, and also the attribute dataset (four node-level variables).

Handbook chapter on centrality

4. The wirings of the world system Arguably the most consequential of all networks is the network infrastructure of the world system. We discuss the import of a network perspective to understand global inequalities and evolving core-periphery structures. We will also introduce UCINET VI - a software dedicated to network analysis. We discuss some basic indices and procedures. Participants will experiment with datasets on international trade.

Smith, David A., and Douglas R. White. 1992. "Structure and Dynamics of the Global Economy: Network Analysis of International Trade 1965-1980." Social Forces 70(4):857-893.
Ingram, Paul, Jeffrey Robinson, and Marc L. Busch. 2005. "The Intergovernmental Network of World Trade: IGO Connectedness, Governance, and Embeddedness." American Journal of Sociology 111(3):824-58.

Assignment: compare two of the datasets in the time series, and test your hypotheses about how international trade has changes with basic indices. You can compare these findings with the network of global cities.

Resources:
Download world trade datasets from 1962, 1970, 1980, 1990, 2000.
Each dataset contains five matrices, corresponding to five levels of export processing (LEP):
LEP1: Food products
LEP2: Low wage light manufacture
LEP3: Simple extractive
LEP4: Sophisticated extractive
LEP4: High tech / heavy manufacture

See Smith et al for details.

The dataset on world cities is available here, and a category vector here.

Handbook chapter on structural equivalence, blockmodels, and roles and positions.

5. Structural holes and brokers - Strategic moves in multiple games The power of networks is not only about the presence of links - it is also about the absence of links. Structural holes are opportunities, and brokers are to profit from them. Brokerage is a general phenomena that can occur in business networks, friendship circles, but also in the webs of the world system. Social networks are always multiplex: networks of friendship, business, political alliances are woven simultaneously. This provides interesting strategic opportunities for insightful players. A key example is the rise of the Medici family in Florence from 1400. Through this example we introduce methods to deal with multiple networks. We use blockmodeling techniques to identify key positions in multiple networks.

Burt, Ronald S. 1995. Structural Holes: The Social Structure of Competition. Harvard University Press. (selections)
Padgett, John F., and Christopher K. Ansell. 1993. "Robust Action and the Rise of the Medici, 1400-1434." American Journal of Sociology 98(6):1259-1319.

Assignment: Use structural equivalence blockmodeling to identify the position of teh Medici in both the marraige and business networks.

Resources:
Use the dataset avaialble in UCINET about Florence: PADGETT. There are two realtions: PADGM recording marriage ties, and PADGB recording business ties.

6. Cohesive groups Birds of a feather flock together - a unique feature of social networks is homophily, the formation of cohesive groups. Groups were among the first phenomena to be discussed about networks as far back as Georg Simmel and the sociometric school. We reconsider groups from a contemporary dynamic take in the areas of academic teams and business groups.

Benjamin F. Jones, et al. 2008. "Multi-University Research Teams: Shifting Impact, Geography, and Stratification in Science." Science 322:1259.
Vedres, Balazs, and David Stark. 2010. "Structural Folds: Generative Disruption in Overlapping Groups." American Journal of Sociology 115(4)
Kossinets, Gueorgi, and Duncan J. Watts. 2009. "Origins of Homophily in an Evolving Social Network." American Journal of Sociology 115(2):405-450.

Assignment: Use the financial firm dataset to identify cohesive groups in the friendship relations, using various methods.

7. Fragile structures: entrepreneurs, coalitions and fragmentation in civic networks Coalition formation is a key process in network building. Social movements are themselves networks of civic organizations. These networks are crucial for social change, yet movement formation is a fragile process that easily fall back to factions and fragmented publics. This is especially complicated today with the strong presence of transnational networks in movement organization. We discuss chances and the potential avenues of movement formation.

Baldassarri, Delia, and Mario Diani. 2007. "The Integrative Power of Civic Networks." American Journal of Sociology 113(3):735-80.
Anheier, Helmut. 2003. "Movement Development and Organizational Networks: The Role of 'Signle Members' in the German Nazi Party, 1925-30." in: Mario Diani, and Doug McAdam (editors): Social Movements and Networks. Oxford: Oxford University Press.

8. Millions on main square: hidden dynamics of civic networks Social movement dynamics is unpredictable - protest activism follows avalanche dynamics, with little action most of the time, punctuated by episodes of massive activism. We explore the nature of complex system dynamics, and discuss potential tactics of triggering such episodes of activism.

Kim, Hyojoung, and Peter S. Bearman. 1997. "The Structure and Dynamics of Movement Participation." Social Forces 62(1):70-93.
Oliver, Pamela E., and Daniel J. Myers. 2003. "Networks, Diffusion, and Cycles of Collective Action." in: Mario Diani, and Doug McAdam (editors): Social Movements and Networks. Oxford: Oxford University Press.

Datasets: Alliances in the Sulukule-disctrict movement.

Assignment: identify the inequalities between local movement networks and the network of NGOs with transnational backing.