Who Are You?

1. Who are you? (Name, year, major)
2. Computational skills (if any)
   • programming, statistical analysis, …
3. What do you want to get from this class?
4. Ask me a question about computational modeling
5. Something interesting about yourself

Getting Started

For Monday:

• Download and install NetLogo on your computer.
  • URL in syllabus and assignment sheet

Agent-Based Modeling

• Simulate individuals:
  • Autonomous
  • Heterogeneous
  • Quasi-local
  • Bounded rationality
• Simulate environment
• Emphasize simplicity, minimal assumptions
• Emergence: Large-scale phenomena arise from small-scale individual interactions
  • Interesting when large-scale is not easily predicted from small-scale

Economics of Cooperation

Game Theory

• Prisoner’s Dilemma Game:

  A \ B	B Cooperates	B Defects
  A Cooperates	(3,3)	(0,4)
  A Defects	(4,0)	(1,1)

• Nash Equilibrium:

  • No matter what player A does, player B is better off defecting
  • No matter what player B does, player A is better off defecting
  • End result: Both players end up worse off than if they had both cooperated.

Iterated Prisoner’s Dilemma

• R. Axelrod (1981)
• Tournament of algorithms
• Winner: “tit-for-tat”
• Evolutionary Game Theory:
  • Basic principles of good strategies:
    • Be nice
    • Be provocable
    • Don’t be too envious
    • Don’t be too clever
• Nay & Gilligan (2015)
  • Real-world strategies involve randomness, unpredictability

Modeling Environment

Constructing model

• Paleoclimate:
  • Assess different kinds of soil
  • Assess tree rings, pollen, etc.
  • Reconstruct drought severity index
• Society:
  • Archaeology gives #, location of households
• Make assumptions about:
  • # people per household,
  • Agriculture,
  • …
• Devise rules for behavior:
  • Marriage, reproduction, migration, …
• Simulate years 800–1300

Results

Comparison

Simulated	Historical

Results