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
From each according to his ability, to each according to his needs can be found in the Guilford Covenant in 1639: Some scholars trace the origin of the phrase to the New Testament. In Acts of the Apostles the lifestyle of the community of believers in Jerusalem is described as communal (without individual possession), and uses the phrase ""distribution was made unto every man according as he had need"" (): However, other scholars disagree with this, and claim that the phrase 'from each according to their abilities, to each according to their needs' has a non-religious origin, in 'the Roman legal concept of obligation in solidum' The Roman legal concept of obligation