Marketing via Friends: Strategic Diffusion of Information in Social Networks with Homophily
Roman Chuhay
Higher School of Economics, ICEF, CAS 2011
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 1 / 20
Marketing via Friends: Strategic Diffusion of Information in Social - - PowerPoint PPT Presentation
Marketing via Friends: Strategic Diffusion of Information in Social Networks with Homophily Roman Chuhay Higher School of Economics, ICEF, CAS 2011 Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 1 / 20 Homophily Homophily is a
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 1 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 2 / 20
◮ In our context - people with similar preferences tend to interact more. Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 2 / 20
◮ In our context - people with similar preferences tend to interact more.
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 2 / 20
◮ Theoretical: Campbell (2010), Goyal and Galeotti (2009), Lopez-Pintado &
◮ Empirical: Leskovec et al. (2008), Iribarren and Moro (2007) Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 3 / 20
◮ Theoretical: Campbell (2010), Goyal and Galeotti (2009), Lopez-Pintado &
◮ Empirical: Leskovec et al. (2008), Iribarren and Moro (2007)
◮ Information diffusion: Currarini, Jackson & Pin (2009), Jackson & Golub
◮ Social norms and preferences: Christakis & Fowler (2007), Fiore and Donath
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 3 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 4 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 4 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 4 / 20
◮ Degree distribution p(k). Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 4 / 20
◮ Degree distribution p(k). ◮ Vector (ρA, ρB) identifies proportion of consumers of the same type in the
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 4 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 5 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 5 / 20
◮ Across types: ⋆ Type A prefers high values of characteristic w ⋆ Type B prefers low values of characteristic w Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 5 / 20
◮ Across types: ⋆ Type A prefers high values of characteristic w ⋆ Type B prefers low values of characteristic w ◮ Within types: ⋆ Reservation price ¯
⋆ Threshold level of the product’s characteristic ¯
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 5 / 20
◮ Across types: ⋆ Type A prefers high values of characteristic w ⋆ Type B prefers low values of characteristic w ◮ Within types: ⋆ Reservation price ¯
⋆ Threshold level of the product’s characteristic ¯
◮ Direct advertisement. ◮ Observing a neighbor who has already acquired the product. Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 5 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 6 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 6 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 6 / 20
◮ Price P ∈ [0, 1] Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 6 / 20
◮ Price P ∈ [0, 1] ◮ Characteristic of the product w ∈ [0, 1] Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 6 / 20
◮ Price P ∈ [0, 1] ◮ Characteristic of the product w ∈ [0, 1]
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 6 / 20
◮ Price P ∈ [0, 1] ◮ Characteristic of the product w ∈ [0, 1]
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 6 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 7 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 7 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 7 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 7 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 7 / 20
◮ Type A: qA = Pr(w ≥ ¯
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 7 / 20
◮ Type A: qA = Pr(w ≥ ¯
◮ Type B: qB = Pr(w ≤ ¯
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 7 / 20
1 P qA 1 P qB
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 8 / 20
1 P qA 1 P qB
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 8 / 20
1 P qA 1 P qB
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 8 / 20
1 P qA 1 P qB
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 8 / 20
1 P qA 1 P qB
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 8 / 20
P P
1 P qA 1 P qB
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 8 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 9 / 20
1
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 9 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 10 / 20
z1 > min{2, ρ−1} there exist combinations of product characteristic and price
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 10 / 20
z1 > min{2, ρ−1} there exist combinations of product characteristic and price
z1 > 1.
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 10 / 20
z1 > min{2, ρ−1} there exist combinations of product characteristic and price
z1 > 1.
z1 < 2 hinges on the
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 10 / 20
1 2
1 Ρ
1 2
1 w
2
2
2
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 11 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 12 / 20
◮ All neighbors are of different type. ◮ Spreading depends on the attractiveness of the product to both types. Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 12 / 20
◮ All neighbors are of different type. ◮ Spreading depends on the attractiveness of the product to both types.
◮ Two clusters of consumers of the same type. ◮ Specialized design is optimal. Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 12 / 20
P PFI 0.5 Ρ 0.5 0.32 P
2 is strictly decreasing function in the level of homophily.
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 13 / 20
1−P 2
z1(1−P) 2−z2/z1(1−P)
2 1−P 2
z1(1−P)
1 ρ −z2/z1(1−P)
2
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 14 / 20
1−P 2
z1(1−P) 2−z2/z1(1−P)
2 1−P 2
z1(1−P)
1 ρ −z2/z1(1−P)
2
1
2
2.
3
P 1−P and is
2.
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 14 / 20
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Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 15 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 15 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 15 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 15 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 15 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 15 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 16 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 16 / 20
◮ Demand is increasing in the level of homophily.
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 16 / 20
◮ Demand is increasing in the level of homophily.
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 16 / 20
◮ Demand is increasing in the level of homophily.
◮ Demand is increasing - more consumers buy the product. ◮ The optimal price is decreasing in the level of homophily.
P∗(ρ)
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 16 / 20
◮ Targeting advertisement is always optimal. ◮ For high enough connectivity the optimal design is the same as without
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 17 / 20
◮ Targeting advertisement is always optimal. ◮ For high enough connectivity the optimal design is the same as without
◮ Bend inward frontier - results are the same. ◮ Bend outward frontier - similar shape, but design is continuous. Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 17 / 20
◮ Targeting advertisement is always optimal. ◮ For high enough connectivity the optimal design is the same as without
◮ Bend inward frontier - results are the same. ◮ Bend outward frontier - similar shape, but design is continuous.
◮ Low levels of homophily - compromise design is still optimal. ◮ High levels of homophily - compromise design is optimal when audience is
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 17 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 18 / 20
0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Ρ w
1 belongs to the interval
2
1 = 0
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Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 19 / 20
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Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 20 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 20 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 20 / 20
Roman Chuhay (ICEF, CAS, HSE) Marketing via Friends 2011 20 / 20