Chapter 4 – Sugar & Spice – Trade Comes to Sugarscape

Sugar, Spice & Trade This chapter is mainly on price No Auctioneer for top-down but a bottom-up emergence effects the price equillibrium Agents have a welfare function, a movement rule Agents have a trade rule Initial Carrying Capacity in Sugar-Spice scape is low Carrying capacity increases but so also the skewness of wealth

Scenario: Lesser Interactions with Vision Vision decreases, price dispersion increases Reason: Agents move around less and hence more price heterogeneity Scenario: Finite Lives: Replacement Replacement comes into effect. Price dispersion increases Reason: More young agents with their MRSs away from the prevailing exist. Price variance increases Price dispersion decreases as the lifetime increases

Scenario – Equity With carrying capacity increased, the inequity increases. Reason: Given the scape situation as-is, there are many agents with diverse wealth content. Scenario – Sexual Reproduction Price dispersion increases Reason: With the new borns, the MRSs are way far from the prevailing levels

Scenario: Culture Price dispersion takes a random walk Reason: Culture is evolving & preferences are constantly changing as the agents are exchanging information. Scenario: Pollution Price dispersion turns exponential With diffusion, it returns to 1 Reason: Agents move from sugar hills and they need sugar. So they buy at high prices. With pollution turned off, they return to sugar hill

Scenario: Credit Rule Evolution of borrowers, lenders and lender- borrowers. Hierarchical evolution emerges Summary: Solving collective problems which the agents cannot solve in isolation. Emergence of equilibrium from the bottom.