Incentive Geometry: Cohomological Obstructions to Cooperation and the Design of Closing Mechanisms

Applies the H^k cohomological complexity ladder to collective action problems and mechanism design. The tragedy of the commons is an H1 obstruction; the tragedy of the horizon (Carney 2015) is an H2 obstruction. The critical coupling theorem gives the minimum carbon price delta* = max(lambda_i - 1) sufficient to make cooperation individually rational — predicting delta* ~ $150-250/tonne CO2 for hard-to-abate sectors, roughly twice the 2024 EU ETS price. Classifies institutions as H0 (price), H1 (regulatory agency), or H2 (structural treaty/BIND). Connects to Friston's Free Energy Principle via multi-agent Markov blankets.