1. Successful Examples of Emergence in the Social Sciences: A partial view, Mark Kuperberg
1.1. Economics
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Mark began by stating that economics offers a rich array of examples of emergent phenomena
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There are often rules defined at the local level
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Mark quoted Adam Smith (invisible hand) to show that he aggregate phenomena that result from these local rules has been invesitaged for some time in economics
1.2. Agregate Phenomena
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There are many examples in which the aggregate phenomena explain good outcomes, for example Smith's invisible hand
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However, there is a gap in how these aggregate phenomea explain "bad outcomes", such as recessions.
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Some economists think that recessions are "cleansing", like a forest fire
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Other economists do not even believe in recessions
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Some economists think that recessions are more like "blood letting"
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In microeconomics there are individual agents with constraints and they optimize according to these constraints then aggregate to get the global phenomena
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Most tools of economics are microeconomic tools
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In macroeconomics one worries about the whole, things like business cycles
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Economists do not fully understand why macroeconomic rules actually describe the economy
1.3. Netlogo Models
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Segregation Model: this is based on Thomas Schelling's segragation model
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Environment contains red and green agents
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The agents have a happiness threshold associated with them
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When the threshold is set to 30%, that means that the agent is happy only when 30% or more of its neighbors are the same color as they are
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If they are happy they stay put, if they are unhappy then they move
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With the threshold set to 30%, the agents in the environment segregate into groups of uniform color
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People have investigates what happens if once the model has reached a stable state (all agents happy) another agent is added. How many changes will this additional agent spawn? This is similar to Per Bak's sandpile avalanches.
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Mark pointed out how low the happiness threshold is when segregation takes place.
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Netlogo Wealth Distribution Model
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Mark briefly demonstrated the wealth distribution model.
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It was interesting to note how easily huge discrepancies in wealth distribution appear
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Ted Wong raised the perspective of Levins, Ch 1, p. 7, On theories and models, there is no single best all-purpose model. No model can exhibit all three of the following charistics at the same time.
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generality
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reality
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precision
