Bargaining or haggling is a type of negotiation in which the buyer and seller of a good or service dispute the price which will be paid and the exact nature of the transaction that will take place, and eventually come to an agreement. Bargaining is an alternative pricing strategy to fixed prices.
Dickering refers to the same process, albeit with a slight negative (petty) connotation.
Not all transactions are open to bargaining. Both religious beliefs and regional custom may determine whether or not the seller is willing to bargain.
In almost all large complex business negotiations, a certain amount of bargaining takes place. One simplified 'western' way to decide when it's time to bargain is to break negotiation into 2 stages: creating value and claiming value. Claiming value is another phrase for bargaining. Many cultures take offence when they perceive the other side as having started bargaining too soon. This offence is usually as a result of their wanting to first create value for longer before they bargain together. The Chinese culture by contrast places a much higher value on taking time to build a business relationship before starting to create value or bargain. Not understanding when to start bargaining has ruined many a otherwise positive business negotiation.
In areas where bargaining at the retail level is common, the option to bargain often depends on the presence of the store's owner. A chain store managed by clerks is more likely to use fixed pricing than an independent store managed by an owner or one of owner's trusted employees.
The store's ambiance may also be used to signal whether or not bargaining is appropriate. For instance, a comfortable and air-conditioned store with posted prices usually do not allow bargaining, but a stall in a bazaar or marketplace may. Supermarkets and other chain stores almost never allow bargaining. However, the importance of ambiance may depend on the cultural commitment to bargaining. In Israel, prices on day-to-day items (clothing, toiletries) may be negotiable even in a Western style store manned by a clerk.
Traditionally, Jews had a limit on the allowable profit margin. Limits were also placed on renegotiations of a price for services.
In a classical bargaining problem the result is an agreement reached between all interested parties, or the status quo of the problem. It is clear that studying how individual parties make their decisions is insufficient for predicting what agreement will be reached. However, classical bargaining theory assumes that each participant in a bargaining process will choose between possible agreements, following the conduct predicted by the rational choice model. It is particularly assumed that each player's preferences regarding the possible agreements can be represented by a von Neumann-Morgenstern utility function.
Nash  defines a classical bargaining problem as being a set of joint allocations of utility, some of which will correspond to that the players would obtain if they reach an agreement, and another which represents what they would get if they failed to do so.
A bargaining game for two players is defined as a pair (F,d) where F is the set of possible joint utility allocations (possible agreements), and d is the disagreement point.
For the definition of a specific bargaining solution is usual to follow Nash's proposal, setting out the axioms this solution should satisfy. Some of the most frequent axioms used in the building of bargaining solutions are efficiency, symmetry, independence of irrelevant alternatives, scalar invariance, monotonicity, etc.
The Nash bargaining solution is the bargaining solution which maximizes the product of agent's utilities on the bargaining set.
The Nash bargaining solution, however, only deals with the simplest structure of bargaining. It is not dynamic (failing to deal with how pareto outcomes are achieved). Instead for situations where the structure of the bargaining game is important, a more mainstream game theoretic approach is useful. This can allow players preferences over time and risk to be incorporated into the solution of bargaining games. It can also show how the detail can matter. For example the Nash bargaining solution for Prisoners' Dilemma is different from the Nash equilibrium.
"Integrative refers to the potential for the parties' interests to be [combined] in ways that create joint value or enlarge the pie." Potential for integration only exists when there are multiple issues involved in the negotiation. This is because the parties must be able to make trade-offs across issues in order for both sides to be satisfied with the outcome.
A very different approach to conceptualizing bargaining is as co-construction of a social narrative, where narrative, rather than economic logic drives the outcome.