Laffer curve at an intermediate rate of taxation, and then falls again to zero revenue at a 100% tax rate. However, the shape of the curve is uncertain and disputed among economists. Under some assumptions, such as revenue being a continuous function of the rate of taxation, the maximum illustrated by the Laffer curve is a result of Rolle's theorem, which is a standard result in calculus. One implication of the Laffer curve is that reducing or increasing tax rates beyond a certain point is counter-productive for raising further tax revenue. A hypothetical Laffer curve for any given economy can only be
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