The Effect of Network Properties on Hysteresis Structure in - - PowerPoint PPT Presentation
The Effect of Network Properties on Hysteresis Structure in - - PowerPoint PPT Presentation
The Effect of Network Properties on Hysteresis Structure in Socio-Ecological System Hendrik Santoso SUGIARTO School of Physical and Mathematical Sciences Human/Nature Interaction Tragedy of the Commons G. Hardin, The Tragedy of The Commons,
Human/Nature Interaction
Tragedy of the Commons
- G. Hardin, The Tragedy of The Commons, Science 163 (3859):344-348
Tragedy of the Commons
- G. Hardin, The Tragedy of The Commons, Science 163 (3859):344-348
Ecological variable Ecological variable Ecological variable
Social Aspect Ecological Aspect
Implications
Will CPR users self-organize? Many policies based on that conclusion
Hardin said never
- Governments must impose certain rules on all forests,
- r fisheries, or water systems
- Or Privatizations of properties
- Results: Many failures
Self-Organization
Many empirical studies show that a lot of CPRs survive by self-management of local communities
Models
- R. Sethi, E. Somanathan, A Simple Model of Collective Action.
- J. Noailly, C. Withagen, J. van den Bergh, Spatial Evolution of Social Norms in a Common-Pool Resource Game.
Tavoni et al., The survival of the conformist: equity-driven ostracism and renewable resource management.
Renewable natural resource Preserve CPR vs exploit CPR
- Sethi et al & Noailly et al : Costly
punishment
- Tavoni et al: Equity-driven ostracism
Ecological Aspect SocialAspect Mechanism
Network
In fact social interaction is constrained by social network Will network properties affect overall cooperation and its stability?
C D C C C C C C D D D D D D D C
ππ’
ππ ππ ππ ππ ππ ππ ππ ππ ππ ππ ππ ππ ππ ππ ππ ππ
Resource Inflow Natural Depreciation Exploitation by Human ππ’+1 = ππ’ + π β π ππ’ ππππ¦
π
β ππΉπ’ππ’ πππ’ππ πππππ π’ β πΉ = ππππ + ππππ π·πππ β πΈππ£ππππ‘ ππ πππ£ππ’πππ ππ£πππ’πππ β πΊ = πΏπΉπ½ππΎ ππ = ππ πΉ πΊ β π₯ππ π€π‘ ππ = ππ πΉ πΊ β π₯ππ πππππ ππ‘π’π ππππ‘π πππβππππ‘π ππ = ππ π€π‘ ππ ππ = ππ β π(ππ) ππ β ππ ππ
C ππππππ ππ’ππ β πππ¦ππππ¨πππ π’ππ’ππ πππππ£πππ’π§ πππ§πππ β πππ ππΉ = 0 β ππ D ππππππ’ππ β πππ¦ππππ¨πππ βππ‘ ππ₯π πππ§πππ β πππ ππΉ = 0 β ππ
Strategy Selection
D D D D D D D C C C C C C C D D D D D D C C C C C C C C ππ D D D D D D ? C C C C C C C ππ ππ ππ ππ ππ ππ ππ ππ
Every time step, a random player selects new strategy
Strategy Mutation
Every mutation period, a random playerβs strategy is changed to the opposite strategy
D D D D D D C C C C C C C C D D D D D D C C C C C C C ? D D D D D D C C C C C C C D
Numerical Result
Complete Network
1 realization ο increase c, decrease c
Network Degree
High degree Low degree
Social Hysteresis
π β ππ€ππ πππ ππππ π π = 50
Ecological Hysteresis
Social Hysteresis
Ecological Hysteresis
Network Topology
Erdos-Renyi Network Scale-Free Network
Effect of Topology
Network Community
π=0.4, modularity=0.35 π=0.2, modularity=0.542
Effect of Community
2 πππππ£πππ’πππ‘ π = 5 2 πππππ£πππ’πππ‘ π = 45
Effect of Community
2 πππππ£πππ’πππ‘ π = 15 4 πππππ£πππ’πππ‘ π = 15
Test Case: 1 Realization, 5 communities
Analytical Approximation
D D D D D D D C C C C C C C
- π πΈ βprobability choose a defector
- π π· πΈ βconditional probability choose a co-
- perator that connected to defector
D D D D D D D C C C C C C C
Transition probability
- Probability of ππ increases by 1
π+ ππ = π πΈ π π· πΈ π£π β π£π + π πΈ 1 ππ
- Probability of ππ decreases by 1
πβ ππ = π π· π πΈ π· (π£π β π£π) + π π· 1 ππ
Master Equation
ππ ππ β 1 π+ ππ β 1 β ππ ππ πβ ππ + ππ ππ + 1 πβ ππ + 1 β ππ ππ π+(ππ)
ππ+1 ππ β ππ ππ =
Fokker-Planck Equation
- Let π
π = ππ π , π’ = π π
- By using Taylor series, expand up to 1
π2
π ππ’ π π
π, π’
= β π ππ
π
π π
π, π’
π+ π
π β πβ π π
+ 1 2 π2 ππ
π 2 π π π, π’ 1
π π+ π
π + πβ(π π)
Langevin Equation
ππ
π
ππ’ = π π·πΈ ππ β ππ ππ πππ πππ
π
β ππ + π(π’)
Ecological Differential Equation
dπ dπ’ = π β π π ππππ¦
2
β ππΉπ
Equilibrium
- The condition for stable and unstable manifold:
π = 0 & π
π
= 0
πβ = βπΉ + πΉ2 + 4π π ππππ¦ ππππ¦
2
2π
π(π·|πΈ) π π
π π
= ππ π
π
Random Connection Assumption
Assume the connection between cooperators and defectors and random π π· πΈ = π π π· π 1 β π· πβπ
Analytical vs Numerical
Improvement on the Assumption
- Assume the distribution of cooperator lies between random distribution and
clustered distribution π(π·|πΈ) π π
π π
= ππ π
π, πβ
(1 β π) π π· πΈ
π πππππ + π π π· πΈ πππ£π‘π’ππ ππ
π π
π π
= ππ(π
π, πβ)
(1 β π) ( π π· πΈ
π ππππππ(π) π
+ π ( π π· πΈ
πππ£π‘π’ππ πππ(π) π
= ππ(π
π, πβ)
π = 1 β π
π π π
Analytical vs Numerical
2 Communities
- For every nodes,
1 β π probability connected to its own community π probability connected to other community
Pair Approximation for 2 Communities
- π π·2 πΈ1 βconditional probability choose a co-operator in
community 2 that connected to defector in community 1
- π π·1 πΈ1 βconditional probability choose a co-operator in
community 1 that connected to defector in community 1
Transition probability
π+ ππ = π πΈ1 1 β π π π·1 πΈ1 + ππ π·2 πΈ1 [π£π β π£π] + π πΈ1 1 ππ + π πΈ2 1 β π π π·2 πΈ1 + ππ π·1 πΈ2 [π£π β π£π] + π πΈ2 1 ππ Probability of πΆπ increases by 1 Probability of ππ decreases by 1
Transition probability
πβ ππ = π π·1 1 β π π πΈ1 π·1 + ππ πΈ2 π·1 [π£π β π£π] + π π·1 1 ππ + π π·2 1 β π π πΈ2 π·1 + ππ πΈ1 π·2 [π£π β π£π] + π π·2 1 ππ Probability of ππ increases by 1 Probability of πΆπ decreases by 1
Social Equilibrium
π πΈ1 1 β π π π·1 πΈ1 + ππ π·2 πΈ1 π π β ππ π
π π π
+ π πΈ2 1 β π π π·2 πΈ2 + ππ π·1 πΈ2 π π β ππ π
π π π
= 0
Communityβs Cooperation
Let π π·1 = π·1, π πΈ1 = 1 β π·1and π π·2 = π·2, π πΈ2 = 1 β π·2 Assume the cooperation spread in one community first before spread to other community ππ π
π < 0.5 π·1 = 2π π·
π·2 = 0 ππ π
π > 0.5
π·1 = 1 π·2 = 2π
π· β 1
Random Connection Assumption
Assume the connection between cooperators and defectors and random
- π π·1 πΈ1 = ππ
π π·1 π 1 β π·1 ππβπ πππ π π·2 π 1 β π·2 πππβπ
- π π·2 πΈ1 = πππ
π π·2 π 1 β π·2 πππβπ ππ π π·1 π 1 β π·1 ππβπ
- π π·1 πΈ2 = πππ
π π·1 π 1 β π·1 πππβπ ππ π π·2 π 1 β π·2 ππβπ
- π π·2 πΈ2 = ππ
π π·2 π 1 β π·2 ππβπ πππ π π·1 π 1 β π·1 πππβπ
Analytical vs Numerical
Conclusion
- The existence of Hysteresis effect and alternate stable
state on socio-ecological network (possibility of Regime Shift)
- High degree network is more robust (strong hysteresis)
- Scale-free network is more robust than Erdos-Renyi
network
- Community structure exhibits multiple hysteresis
Thank You
Appendix
- Early Warning Signals
- Empirical Data
Early Warning Signals
- Temporal EWSs
- Spatial EWSs
- Time Series Data Collection
- Filtering-detrending
- Rolling Windows
- Time Series Analysis for Early Warning indicators
- Significance Test
Temporal Early Warning
Test Model vs Null Model
Temporal Early Warning
The effect of network degree on temporal EWS
- Spatial autocorrelation is characterized by a correlation among
nearby nodes in network π½ = π π₯ππ
π π
π₯ππ
π π
ππ β π π
π β π
ππ β π 2
π
π₯ππ = 1 ππ π πππ π ππ‘ πππππππ’ππ, 0 ππ’βππ π₯ππ‘π
- Spatial Standard deviation, skewness, and kurtosis are defined as
second, third, and fourth moment of spatial distribution π2 =
ππβπ 2
π
π
πΏ =
ππβπ 3
π
π3
π =
ππβπ 4
π
π4
Spatial Early Warnings
- Denote every nodes with strategy C with value 1
and every nodes with strategy D with value 0
D D D D D D D C C C C C C C
i j π₯ππ = 0 ππ = 0 π
π = 1
Moran I
- Denote every nodes with strategy C with value 1
and every nodes with strategy D with value 0
D D D D D D D C C C C C C C
i j π₯ππ = 1 ππ = 0 π
π = 1
Moran I
- Denote every nodes with strategy C with value 1
and every nodes with strategy D with value 0
D D D D D D D C C C C C C C
i j π₯ππ = 1 ππ = 0 π
π = 0
Moran I
Spatial Indicators
The effect of network degree on spatial EWS
Empirical Data
- Survey data collected by an anthropologist from
Arizona university, J S Lansing
- Location: Bali, Indonesia
- 20 Subaks (villages)
Farmers Opinion From Survey
Name Caste Class Condition of Subak Water Shortage β¦ Farmer 1 3 3 3 4 β¦
- Are water shortages frequent in the subak during the dry season?
A never coded as 4 B seldom coded as 3 C sometimes 2 D Frequent 1
- The condition of your subak now is:
A Excellent, still intact coded as 5 B Good enough coded as 4 C some problems have begun 3 D not good 2 E Bad 1 Example of the questions
Name Caste Class Condition of Subak Water Shortage β¦ Farmer 1 3 3 4 2 β¦ Farmer 2 3 3 4 2 β¦ Farmer 3 3 3 5 1 β¦ β¦ β¦ β¦ β¦ β¦ β¦ Farmer i 3 2 3 2 β¦ Farmer i+1 3 3 4 2 β¦ Farmer i+2 1 2 2 1 β¦ β¦ β¦ β¦ β¦ β¦ β¦ β¦ β¦ β¦ β¦ β¦ β¦ Subak 1 Subak 2
Principal Component Analysis
Biplot Projection
Data vs Model
Very cooperative