Number systems are shared social technologies. They are heterogeneous, differing along dimensions of modality, base, and marking. These characteristics impart differential advantages depending on purpose and context, which explains why most cultures employ multiple number systems simultaneously. Number systems are embedded in patterns of complementarity involving both human and physical capital. Viewing number systems this way allows us to apply economic insights about production, cost, and technology to things often regarded as purely abstract cognitive conventions. Combining these insights with the literature on 4E cognition shows how concrete economic factors can shape key aspects of how humans think.
