Laffer curve rates (for example, in the United States by the Congressional Budget Office). While the interaction between tax rates and tax revenue is generally accepted, the precise nature of this interaction is debated. In practice, the shape of a hypothetical Laffer curve for a given economy can only be estimated. The relationship between tax rate and tax revenue is likely to vary from one economy to another and depends on the elasticity of supply for labor, as well as various other factors. Even in the same economy, the characteristics of the curve could vary over time. Complexities such as progressive taxes
Contract curve the initial allocations. The analysis cannot say which particular point along the contract curve they will end up at — this depends on the two people's bargaining skills. In the case of two goods and two individuals, the contract curve can be found as follows. Here formula_1 refers to the final amount of good 2 allocated to person 1, etc., formula_2 and formula_3 refer to the final levels of utility experienced by person 1 and person 2 respectively, formula_4 refers to the level of utility that person 2 would receive from the initial allocation without trading at all, and formula_5