Rateutility

Rateutility is a term used in optimization and economic theory to denote a utility function that depends on a rate variable, such as data throughput, production rate, or arrival rate. It captures how satisfaction changes as the rate of provision of a good or service changes. It is not a universally standardized term and may be used informally across disciplines to describe rate-based utility functions.

In mathematical terms, rateutility is a function U(R) where R ≥ 0, typically increasing and concave to reflect diminishing marginal returns: U'(R) > 0, U''(R) < 0. Examples include U(R) = a log(1 + bR) or U(R) = c R^p with 0 < p < 1.

The concept appears in contexts like network utility maximization, where agents choose transmission rates to maximize the sum of rateutilities subject to capacity constraints. It is also used in cloud services, energy management, and production planning to represent user or system satisfaction as flow rates increase.

Rateutility emphasizes rate rather than total quantity, enabling models that value speed or bandwidth and informing pricing, allocation, and control strategies.

See also: utility function, concave function, network utility maximization, bandwidth allocation, rate control.