Counterfactual Simulation for Mining-Shipping Project Design: Building and Comparing Alternative Economic Worlds

A mine is not just a deposit. It is a deposit tied to a route to market. For a bulk mineral project, the economics of extraction can be changed by the rail link, the port window, the terminal contract, the loading equipment, the reliability of access, and the decision rule used to judge the project. A project that looks marginal to a private firm may look different to a public authority if wider benefits are counted, and different again to a strategic planner if reliable mineral supply is the central objective. This article develops counterfactual simulation as a method for making those alternative economic worlds explicit. The worked example is a stylized mining-shipping prototype. Its immediate lineage is Bell (2026a), MPRA Paper No. 127815, which supplies the inherited toy-model basis for the mine-port economics. The article uses that base to construct a curated eight-world experiment rather than presenting the full 54-world laboratory in the body. The experiment follows a simple economic story: the baseline project sits near the private margin; governance costs and disruption can strengthen the case for modification; deposit scale changes the burden of fixed infrastructure and access costs; and public or strategic objectives can change the decision category without changing the physical project. The contribution is methodological but grounded in a concrete project-design problem. Counterfactual simulation helps the analyst see that viability is not a property of the orebody alone. It is a result of a complete world: deposit, logistics, governance, shock environment, institution, and objective. AI-assisted research expands the feasible set of such worlds an individual researcher can build. Human governance defines the admissible model space by deciding which worlds, assumptions, outputs, and interpretations are suitable for use.