Demandn

Demandn is a term used in certain economic models to denote the quantity demanded of a particular good, indexed by n, within a system of multiple goods. The notation is common in computational simulations and in teaching to distinguish the demand for each good in a vector of demands.

In these models, demand_n is typically a function of prices p = (p_1, ..., p_N), income y, and possibly expectations or other state variables. It may be derived from a consumer utility maximization problem (Marshallian demand) or specified directly in a reduced-form demand system. The subscript n signals the nth good in a catalog or network. The concept is often employed in multi-good or networked settings to track how demand shifts across a range of products.

Relation to other concepts: demand_n is a specialization of the general demand function and can exhibit cross-price effects; the cross partial ∂D_n/∂p_m captures how the demand for good n responds to the price of good m. In network or multi-market models, the vector D = (D_1, ..., D_N) may interact through shared income, time constraints, or substitutability/complementarity relationships.

Usage and status: The term is not part of the standard canon of economics and is used variably across texts. It commonly appears in academic papers, simulations, or course notes that model multi-good demand, but is not a universally adopted notation.

See also: demand function, elasticity of demand, cross-price elasticity, consumer theory.