Topics for the Master Thesis

Roman Chuhay,Higher School of Economics

2013

Roman Chuhay (HSE) Topics for the Master Thesis 2013 1 / 20

Outline of the Presentation

Personal Information

Some visual examples of Networks.

Types of networks and research questions.

Networks and/vs. ξconomics.

Main sources of information.

Selected topics.

Work in progress.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 2 / 20

Outline of the Presentation

Personal Information

Some visual examples of Networks.

Types of networks and research questions.

Networks and/vs. ξconomics.

Main sources of information.

Selected topics.

Work in progress.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 2 / 20

Outline of the Presentation

Personal Information

Some visual examples of Networks.

Types of networks and research questions.

Networks and/vs. ξconomics.

Main sources of information.

Selected topics.

Work in progress.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 2 / 20

Outline of the Presentation

Personal Information

Some visual examples of Networks.

Types of networks and research questions.

Networks and/vs. ξconomics.

Main sources of information.

Selected topics.

Work in progress.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 2 / 20

Personal Information

Roman Chuhay (home page)

Research Interests:

Microeconomics, Social Networks, Financial Economics, IndustrialOrganization, Economics of Information, Labor Economics

Key Topics:

Diffusion of information and word of mouth.

The impact of social networks on banks’ stability and financial system as awhole.

Cheap talk and signaling.

Labor markets (Mortensen-Pissarides framework).

Roman Chuhay (HSE) Topics for the Master Thesis 2013 3 / 20

Visual Examples of Networks 1

Figure: Map of the 2004 U.S. Presidential election by counties (M. Newman).

Roman Chuhay (HSE) Topics for the Master Thesis 2013 4 / 20

Visual Examples of Networks 1 contd

Figure: The network structure of political blogs prior to the 2004 U.S. Presidentialelection reveals two natural and well-separated clusters. Moreover conservative blogs onaverage have more links compared to liberal (Adamic and Glance, 2005).

Roman Chuhay (HSE) Topics for the Master Thesis 2013 5 / 20

Visual Examples of Networks 2

Figure: The social network of friendships within a 34-person karate club provides clues tothe fault lines that eventually split the club apart (Zachary, 1977).

Roman Chuhay (HSE) Topics for the Master Thesis 2013 6 / 20

Visual Examples of Networks 2

Figure: Community structure identified by Girvan and Newman 2002. As you can see allnodes were correctly placed in the communities apart the node 3.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 7 / 20

Visual Examples of Networks 3

Figure: The network of loans among financial institutions can be used to analyze theroles that different participants play in the financial system, and how the interactionsamong these roles affect the health of individual participants and the system as a whole.(Bech and Atalay 2008)

Roman Chuhay (HSE) Topics for the Master Thesis 2013 8 / 20

Visual Examples of Networks 4

Figure: When people are influenced by the behaviors of their neighbors in the network,the adoption of a new product or innovation can cascade through the network structure.Here is e-mail recommendations for a First aid study guide: First Aid for the USMLEStep (Leskovec et al. 2007)

Roman Chuhay (HSE) Topics for the Master Thesis 2013 9 / 20

Visual Examples of Networks 5 cont’d

Figure: Recommendations network for a Japanese graphic novel spread in a kind ofinformational or social contagion. (Leskovec et al. 2007)

Roman Chuhay (HSE) Topics for the Master Thesis 2013 10 / 20

Visual Examples of Networks 6

Figure: Percentage of total corn acreage planted with hybrid seed. (USDA AgriculturalStatistics)

Roman Chuhay (HSE) Topics for the Master Thesis 2013 11 / 20

Types of Networks:

Social and economic networks: A set of people or groups of people with somepattern of contacts or interactions between them.

I Facebook, friendship networks, business relations between companies,intermarriages between families, labor markets

Questions: Connectedness, homophily, key-players, small-world effects

Information networks: Connections of ”information” objects.I Network of citations between academic papers, World Wide Web (network of

Web pages containing information with links from one page to other),semantic (how words or concepts are linked to each other)

Questions: Ranking, navigation

Roman Chuhay (HSE) Topics for the Master Thesis 2013 12 / 20

Types of Networks:

Social and economic networks: A set of people or groups of people with somepattern of contacts or interactions between them.

I Facebook, friendship networks, business relations between companies,intermarriages between families, labor markets

Questions: Connectedness, homophily, key-players, small-world effects

Information networks: Connections of ”information” objects.I Network of citations between academic papers, World Wide Web (network of

Web pages containing information with links from one page to other),semantic (how words or concepts are linked to each other)

Questions: Ranking, navigation

Roman Chuhay (HSE) Topics for the Master Thesis 2013 12 / 20

Types of Networks:

Social and economic networks: A set of people or groups of people with somepattern of contacts or interactions between them.

I Facebook, friendship networks, business relations between companies,intermarriages between families, labor markets

Questions: Connectedness, homophily, key-players, small-world effects

Information networks: Connections of ”information” objects.I Network of citations between academic papers, World Wide Web (network of

Web pages containing information with links from one page to other),semantic (how words or concepts are linked to each other)

Questions: Ranking, navigation

Roman Chuhay (HSE) Topics for the Master Thesis 2013 12 / 20

Types of Networks:

Technological networks: Designed typically for distribution of a commodity orservice.

I Infrastructure networks: e.g., Internet (connections of routers or administrativedomains), power grid.

I Transportation networks: roads, railroads, airline routes, mail services.

Questions: Performance? Congestion? Fragility? Cascading failures?

Biological networks: A number of biological systems can also be representedas networks.

I Food web, protein interaction network, network of metabolic pathways

Questions: Stability of the eco-system? Designing of a new drug taking intoaccount protein interaction networks, etc.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 13 / 20

Types of Networks:

Technological networks: Designed typically for distribution of a commodity orservice.

I Infrastructure networks: e.g., Internet (connections of routers or administrativedomains), power grid.

I Transportation networks: roads, railroads, airline routes, mail services.

Questions: Performance? Congestion? Fragility? Cascading failures?

Biological networks: A number of biological systems can also be representedas networks.

I Food web, protein interaction network, network of metabolic pathways

Questions: Stability of the eco-system? Designing of a new drug taking intoaccount protein interaction networks, etc.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 13 / 20

Types of Networks:

Technological networks: Designed typically for distribution of a commodity orservice.

I Infrastructure networks: e.g., Internet (connections of routers or administrativedomains), power grid.

I Transportation networks: roads, railroads, airline routes, mail services.

Questions: Performance? Congestion? Fragility? Cascading failures?

Biological networks: A number of biological systems can also be representedas networks.

I Food web, protein interaction network, network of metabolic pathways

Questions: Stability of the eco-system? Designing of a new drug taking intoaccount protein interaction networks, etc.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 13 / 20

Networks and/vs. ξconomics

Traditionally, economic phenomena are studied in the framework ofcentralized markets:

I Interactions are anonymous.

I Prices are main coordination mechanism.

This approach, however, is inappropriate for understanding of a number ofphenomena:

I Diffusion of innovations

I Job search through contacts

I Differences in trust and cooperativeness

Roman Chuhay (HSE) Topics for the Master Thesis 2013 14 / 20

Networks and/vs. ξconomics

Traditionally, economic phenomena are studied in the framework ofcentralized markets:

I Interactions are anonymous.

I Prices are main coordination mechanism.

This approach, however, is inappropriate for understanding of a number ofphenomena:

I Diffusion of innovations

I Job search through contacts

I Differences in trust and cooperativeness

Roman Chuhay (HSE) Topics for the Master Thesis 2013 14 / 20

Networks and/vs. ξconomics

Traditionally, economic phenomena are studied in the framework ofcentralized markets:

I Interactions are anonymous.

I Prices are main coordination mechanism.

This approach, however, is inappropriate for understanding of a number ofphenomena:

I Diffusion of innovations

I Job search through contacts

I Differences in trust and cooperativeness

Roman Chuhay (HSE) Topics for the Master Thesis 2013 14 / 20

Networks and/vs. ξconomics

Traditionally, economic phenomena are studied in the framework ofcentralized markets:

I Interactions are anonymous.

I Prices are main coordination mechanism.

This approach, however, is inappropriate for understanding of a number ofphenomena:

I Diffusion of innovations

I Job search through contacts

I Differences in trust and cooperativeness

Roman Chuhay (HSE) Topics for the Master Thesis 2013 14 / 20

Networks and/vs. ξconomics

Traditionally, economic phenomena are studied in the framework ofcentralized markets:

I Interactions are anonymous.

I Prices are main coordination mechanism.

This approach, however, is inappropriate for understanding of a number ofphenomena:

I Diffusion of innovations

I Job search through contacts

I Differences in trust and cooperativeness

Roman Chuhay (HSE) Topics for the Master Thesis 2013 14 / 20

Networks and/vs. ξconomics

Traditionally, economic phenomena are studied in the framework ofcentralized markets:

I Interactions are anonymous.

I Prices are main coordination mechanism.

This approach, however, is inappropriate for understanding of a number ofphenomena:

I Diffusion of innovations

I Job search through contacts

I Differences in trust and cooperativeness

Roman Chuhay (HSE) Topics for the Master Thesis 2013 14 / 20

Main sources of Info

General public books:I N. A. Christakis, J. H. Fowler “Connected: The Surprising Power of Our

Social Networks and How They Shape Our Lives.”

I D. J. Watts, “Six Degrees: The Science of a Connected Age.”

I A.-L. Barabasi, “Linked: How Everything Is Connected to Everything Else andWhat It Means.”

Roman Chuhay (HSE) Topics for the Master Thesis 2013 15 / 20

Main sources of Info

Text books and surveys:I Vega-Redondo, F. (2007), “Complex Social Networks. Econometric Society

Monographs,” Cambridge: Cambridge University Press.

I Goyal, S. (2007), “Connections: An Introduction to the Economics ofNetworks,” Princeton University Press.

I Jackson, M.O. (2008), “Social and Economic Networks,” Princeton: PrincetonUniversity Press.

I Newman, M. (2010), “Networks: An Introduction,” Oxford University Press.

I Newman, M. E. J. (2003): ”The structure and function of complex networks”,SIAM Review 45, 167-256

Roman Chuhay (HSE) Topics for the Master Thesis 2013 16 / 20

Selected Topics

Diffusion on networks:I Campbell, A., 2009, “Tell Your Friends! Word of Mouth and Percolation in

Social Networks,” job-market paper.

I Galeotti, A. and Goyal, S., 2008, “A Theory of Strategic Diffusion,”forthcoming in Rand Journal of Economics.

I Leskovec, J., Adamic, L. A. and Huberman, B. A., 2007, “The Dynamics ofViral Marketing,” In Proc. 7th ACM Conference on Electronic Commerce.

I Newman, M., 2002, “The Spread of Epidemic Diseases on Networks,” PhysicalReveiw E, Volume 66(1), art. no. 016128.

I Newman, M., 2003, “Mixing patterns in networks,” Physical Reveiw E,Volume 67, art. no. 026126.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 17 / 20

Selected Topics

Labor markets and networks:I Granovetter, M., 1973, “The Strength of Weak Ties,” American Journal of

Sociology, Vol. 78, Issue 6, pp. 1360-1380.

I Boorman S.A., 1975, “A Combinatiorial Optimization Model for Transmissionof Job Information Through Contact Networks,” The Bell Journal ofEconomics, Vol. 6, pp. 216-249.

I Calvo-Armengol A., Zenou Y., 2005, “Job matching, social network andword-of-mouth communication,” Journal of Urban Economics, 57, pp. 500522.

I Calvo-Armengol, A., Jackson, M.O., 2004, “The Effects of Social Networks onEmployment and Inequality,” American Economic Review, 94(3), pp. 426454.

I Galeotti A., Merlino L.P.,, 2009, “Endogenous Job Contact Networks,”manuscript, University of Essex.

I Ioannides Y.M., Soetevent A.R., 2006, “Wages and Employment in a RandomSocial Network with Arbitrary Degree Distribution,” The American EconomicReview, Vol. 96, pp. 270-274.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 18 / 20

Selected Topics

Network formation:I Bala, V. and S. Goyal (1999), “A Non-Cooperative Model of Network

Formation,” Econometrica, 1181-1230.

I Jackson, M.O. and A. Wolinsky (1996), “A strategic model of economic andsocial networks,” Journal of Economic Theory, 71, 44-74.

I Jackson, M.O. and B. Rogers (2007), “Meeting strangers and friends offriends: How random are socially generated networks?” American EconomicReview, 97(3), 890-915.

Roman Chuhay (HSE) Topics for the Master Thesis 2013 19 / 20

Erdos Number

Erdos number 0 — 1 personErdos number 1 — 504 peopleErdos number 2 — 6593 peopleErdos number 3 — 33605 peopleErdos number 4 — 83642 peopleErdos number 5 — 87760 peopleErdos number 6 — 40014 peopleErdos number 7 — 11591 peopleErdos number 8 — 3146 peopleErdos number 9 — 819 peopleErdos number 10 — 244 peopleErdos number 11 — 68 peopleErdos number 12 — 23 peopleErdos number 13 — 5 people

Roman Chuhay (HSE) Topics for the Master Thesis 2013 20 / 20