Voluntary exchange

A transfer of goods, services, or rights in which participants consent to trade on mutually accepted terms. It contrasts with transfers imposed by force or without agreement.

Consent: Agreement to an action or arrangement, given freely by a person with the capacity to decide. Voluntary exchange depends on participants accepting the trade rather than having it imposed.
Property rights: Socially and legally recognized claims over resources, including rights to use, exclude others, and transfer them. Participants need recognized authority to transfer the goods or rights involved in a trade.
Barter: The direct exchange of goods or services without using money as an intermediary. Barter is a clear case of voluntary exchange whose terms are negotiated directly.
Coercion: The use or threat of force, or other pressure, to make someone act against their choice. Coercion distinguishes imposed transfers from exchanges based on consent.
Pareto efficiency: An allocation is Pareto efficient if no change can make someone better off without making someone else worse off. Under restrictive assumptions, mutually beneficial trades can move an allocation toward Pareto efficiency.
Bargaining: A process in which parties negotiate terms to reach an agreement. Participants can negotiate price, quantity, and other terms before consenting to trade.
Private property: Property held by individuals or organizations that can generally exclude others from its use. Private ownership often gives holders the ability to offer assets in voluntary exchanges.
Labor market: A market in which workers offer labor and employers seek it under agreed conditions. Employment exchanges labor for wages and other agreed compensation.
Fraud: Intentional deception used to secure an unfair or unlawful gain. A deceptive transaction may involve apparent agreement without informed consent.
Consumer surplus: The difference between what a buyer is willing to pay and what the buyer actually pays. A buyer's surplus measures one possible gain from a completed exchange.

Linked from 5 pages