my talk at Zuricher Kamingespraeche.

1. Towards a
democratic, scalable, and sustainable
digital future
(a complex systems perspective)
@KoljaKleinebergkkleineberg@ethz.chKaj Kolja Kleineberg koljakleineberg.wordpress.com

2. Complex system?
What is a

3. » ...the whole is more than the sum of the parts, [...]
in the sense that, given the properties of the parts and
the laws of their interaction, it is not a trivial matter to
infer the properties of the whole.«
Herbert A. Simon

4. » ...the whole is more than the sum of the parts, [...]
in the sense that, given the properties of the parts and
the laws of their interaction, it is not a trivial matter to
infer the properties of the whole.«
Herbert A. Simon
Large number
of components

5. » ...the whole is more than the sum of the parts, [...]
in the sense that, given the properties of the parts and
the laws of their interaction, it is not a trivial matter to
infer the properties of the whole.«
Herbert A. Simon
Large number
of components
Nonlinear
interactions

6. » ...the whole is more than the sum of the parts, [...]
in the sense that, given the properties of the parts and
the laws of their interaction, it is not a trivial matter to
infer the properties of the whole.«
Herbert A. Simon
Large number
of components
Nonlinear
interactions
Emergence
& self-organization

8. the human brain

9. How can we deal with complex systems?

10. How can we deal with complex systems?
Complex networks useful tools

11. Networks allow us to map the interactions
and study system-level implications
Nature Physics 10, 762-767 (2014) • Phys. Rev. Lett. 109, 064101 (2013)

12. Networks often provide useful maps
of complex systems
Nature Communications 1, 62 (2010)

13. Networks are powerful tools
to solve diverse problems
Credits: Marian Boguna

14. Networks are powerful tools
to solve diverse problems
Credits: Marian Boguna

15. Networks are powerful tools
to solve diverse problems
Credits: Marian Boguna

16. Networks are powerful tools
to solve diverse problems
Credits: Marian Boguna

17. Networks are powerful tools
to solve diverse problems
Credits: Marian Boguna

18. Networks are powerful tools
to solve diverse problems
Credits: Marian Boguna

19. my story

20. When I was 11 years old...

21. 56k modem
... I got my first

22. now, 2 decades later...

23. online social network users
2+ billion
internet users
3+ billion

24. networked devices by 2020
50 billion

25. could lead to
Collective Intelligence

26. but also to
Monopolies of Information

27. vision of our digital future.
We need a
democratic,
scalable,
sustainable

28. Evolution of isolated online social networks unfolds
on top of underlying social structure
Online social
network layer
Traditional contact
network layer
Active
Online & offline
Passive
Online & offline
Susceptible
Only offline
Mass media activation Viral activation
Deactivation Viral reactivation
Physical Review X (4) 031046 (2014)

29. Digital ecosystem is formed by multiple networks
competing for the attention of individuals
OSN 2
OSN 1
Underl.
network
Active
Passive
Susceptible
Partial
states}
Virality share
distribution
between OSNs
λi = ωi(ρa)λ
Rich-get-richer
more active
networks obtain
higher share
Here: ωi = [ρa
i ]σ/
∑
j[ρa
j]σ
σ: activity affinity
Sci. Rep. 5, 10268 (2015)

30. Coexistence (diversity) is possible but fragile:
once lost, it cannot be recovered
Stable
Unstable
0.50 0.75 1.00 1.25 1.50
0.00
0.25
0.50
0.75
0.00
0.25
0.50
0.75
Bifurcation diagram
σ
ρ1,2
a
Sci. Rep. 5, 10268 (2015)

31. Coexistence (diversity) is possible but fragile:
once lost, it cannot be recovered
Stable
Unstable
0.50 0.75 1.00 1.25 1.50
0.00
0.25
0.50
0.75
0.00
0.25
0.50
0.75
Bifurcation diagram
σ
ρ1,2
a
Coexistence
despite rich-get-richer
Sci. Rep. 5, 10268 (2015)

32. Coexistence (diversity) is possible but fragile:
once lost, it cannot be recovered
Stable
Unstable
0.50 0.75 1.00 1.25 1.50
0.00
0.25
0.50
0.75
0.00
0.25
0.50
0.75
Bifurcation diagram
σ
ρ1,2
a
Coexistence
despite rich-get-richer
Digital diversity
is fragile
Sci. Rep. 5, 10268 (2015)

33. Utility of networks: bottom-up search and navigation
with incentives based on sharing generated value
Individuals
perform routing
instead of service
providers
Routing
information is
rewarded
(cryptocurrency)
Payoff
for successful
deliveries
Nature Communications 1, 62 (2010) • arXiv:1611.04395 (accepted in Sci. Rep.)

34. Scalable navigation using only local knowledge
performs better if more networks coexist
Nature Physics 12, 1076–1081 (2016)

35. Scalable navigation using only local knowledge
performs better if more networks coexist
Nature Physics 12, 1076–1081 (2016)

36. Scalable navigation using only local knowledge
performs better if more networks coexist
Nature Physics 12, 1076–1081 (2016)

37. Scalable navigation using only local knowledge
performs better if more networks coexist
Nature Physics 12, 1076–1081 (2016)

38. Scalable navigation using only local knowledge
performs better if more networks coexist
Nature Physics 12, 1076–1081 (2016)

39. Scalable navigation using only local knowledge
performs better if more networks coexist
Nature Physics 12, 1076–1081 (2016)

40. Scalable navigation using only local knowledge
performs better if more networks coexist
Nature Physics 12, 1076–1081 (2016)

41. Appropriate incentives could create a feedback loop
building on self-organization of complex systems
Qualified Money
t
o
route
activein
m
any networks
Optim
izes strategy:
Inc
entive
Sustains
digital dive
rsity
Increasesro
uting
perform
a
nce
Exchangeable
Social Bitcoin
+Reputation
Eur. Phys. J. Spec. Top. 225: 3231 (2016)

42. Tendency to be active in several networks simultaneously
influences distribution of attention between networks
Attention share
distribution
between OSNs
λi = ωi(ρa)λ
ωi(ρa
) =
[ρa
i ]σ
∑nl
j=1
[
ρa
j
]σ
rich-get-richer
Eur. Phys. J. Spec. Top. 225: 3231 (2016)

43. Tendency to be active in several networks simultaneously
influences distribution of attention between networks
Attention share
distribution
between OSNs
λi = ωi(ρa)λ
ωi(ρa
) =
[ρa
i ]σ
∑nl
j=1
[
ρa
j
]σ
rich-get-richer
+ ξ(⟨ρa
⟩ − ρa
i )
navigation incentive
Eur. Phys. J. Spec. Top. 225: 3231 (2016)

44. Tendency to be active in several networks simultaneously
influences distribution of attention between networks
Attention share
distribution
between OSNs
λi = ωi(ρa)λ
ωi(ρa
) =
[ρa
i ]σ
∑nl
j=1
[
ρa
j
]σ
rich-get-richer
+ ξ(⟨ρa
⟩ − ρa
i )
navigation incentive
ξ = 0.2 ξ = 1.0
Stable
Unstable
0.5 1.0 1.5 2.0
0.0
0.2
0.4
0.6
0.8
σ
ρ1,2
a
Stable
Unstable
1.5 2.0 2.5 3.0
0.0
0.2
0.4
0.6
0.8
σ
ρ1,2
a
Eur. Phys. J. Spec. Top. 225: 3231 (2016)

45. A democratic, scalable, and sustainable digital future:
Appropriate incentive system could lead to sustainability
to route
strategy
Optimizes
Incentive
Sustains
digital diversity
Increases routing
performance
Social Bitcoin
+Reputa�onStable
Unstable
0.50 0.75 1.00 1.25 1.50
0.00
0.25
0.50
0.75
0.00
0.25
0.50
0.75
Bifurcation diagram
ρ1
a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
FrameworkResultFocus
Digital
PRX 4, 031046
Sci. Rep. 5, 10268
Sci. Rep. 6, 25116
Scalable Sustainability
Is digital diversity
possible?
Search and navigation
with local knowledge
Incentives sustain diverse
decentralized digital world
Network evolution &
competition
Geometric correlations,
mutual greedy routing
Digital diversity is
possible but fragile
Routing perfected by
using many networks
Digital diversity becomes
robust & routing improves
Refs
Nature Physics 12,
1076–1081 (2016)
Eur. Phys. J. Spec. Top.
225: 3231 (2016)
Cryptocurrency as incen-
tive to route information
navigationdiversity & robustness

46. A democratic, scalable, and sustainable digital future:
Appropriate incentive system could lead to sustainability
to route
strategy
Optimizes
Incentive
Sustains
digital diversity
Increases routing
performance
Social Bitcoin
+Reputa�onStable
Unstable
0.50 0.75 1.00 1.25 1.50
0.00
0.25
0.50
0.75
0.00
0.25
0.50
0.75
Bifurcation diagram
ρ1
a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
FrameworkResultFocus
Digital
PRX 4, 031046
Sci. Rep. 5, 10268
Sci. Rep. 6, 25116
Scalable Sustainability
Is digital diversity
possible?
Search and navigation
with local knowledge
Incentives sustain diverse
decentralized digital world
Network evolution &
competition
Geometric correlations,
mutual greedy routing
Digital diversity is
possible but fragile
Routing perfected by
using many networks
Digital diversity becomes
robust & routing improves
Refs
Nature Physics 12,
1076–1081 (2016)
Eur. Phys. J. Spec. Top.
225: 3231 (2016)
Cryptocurrency as incen-
tive to route information
navigationdiversity & robustness

47. A democratic, scalable, and sustainable digital future:
Appropriate incentive system could lead to sustainability
to route
strategy
Optimizes
Incentive
Sustains
digital diversity
Increases routing
performance
Social Bitcoin
+Reputa�onStable
Unstable
0.50 0.75 1.00 1.25 1.50
0.00
0.25
0.50
0.75
0.00
0.25
0.50
0.75
Bifurcation diagram
ρ1
a
0.0 0.5 1.0 1.5
0.50
0.75
σ
σ
ρ1,2
a
FrameworkResultFocus
Digital
PRX 4, 031046
Sci. Rep. 5, 10268
Sci. Rep. 6, 25116
Scalable Sustainability
Is digital diversity
possible?
Search and navigation
with local knowledge
Incentives sustain diverse
decentralized digital world
Network evolution &
competition
Geometric correlations,
mutual greedy routing
Digital diversity is
possible but fragile
Routing perfected by
using many networks
Digital diversity becomes
robust & routing improves
Refs
Nature Physics 12,
1076–1081 (2016)
Eur. Phys. J. Spec. Top.
225: 3231 (2016)
Cryptocurrency as incen-
tive to route information
navigationdiversity & robustness

48. Take home

49. digital future is possible.
A
democratic,
scalable,
sustainable

50. Kaj Kolja Kleineberg:
• kkleineberg@ethz.ch
• @KoljaKleineberg
• koljakleineberg.wordpress.com
ETH Zurich:
• Computational Social Science Group
• http://www.coss.ethz.ch

51. Kaj Kolja Kleineberg:
• kkleineberg@ethz.ch
• @KoljaKleineberg ← Slides & updates
• koljakleineberg.wordpress.com
ETH Zurich:
• Computational Social Science Group
• http://www.coss.ethz.ch