Marginal utility and scarcity need a couple of additional assumptions for price determination to work as intended. First, all humans have to be one-dimensional utility calculators who know what’s best for themselves, what price to pay for what commodity and how to make an economically ‘rational’ choice.11 Second, there must be no interference, for example by monopolies, in price-setting. ‘Equilibrium’ with ‘perfect competition’–in which supply and demand are exactly balanced,
