Power-Law Markets 2D: Preferential Attachment & Gini Lab

A 2D redraw of the preferential-attachment market model: N firms start out with roughly even shares of a market and, each step, new demand is allocated by a rich-get-richer rule — bigger firms attract disproportionately more of it, the mechanism behind network effects and "superstar" winner-take-most markets. Three linked panels — a rank-size bar chart, a Lorenz curve, and a Gini/effective-competitor history strip — track how attachment strength, the new-entrant floor, random luck and firm count reshape market concentration in real time.