Laffer curve and many others advocate a zero capital gains rate. The increased aggregate supply would result in increased aggregate demand, hence the term "supply-side economics". Laffer assumes that the government's revenue is a continuous function of the tax rate. However, in some theoretical models, the Laffer curve can be discontinuous, leading to an inability to devise a revenue-maximizing tax rate solution. Additionally, the Laffer curve depends on the assumption that tax revenue is used to provide a public good that is separable in utility and separate from labor supply, which may not be true in practice. The Laffer curve as presented
From each according to his ability, to each according to his needs in solidum is that 'everyone assumes responsibility for anyone who cannot pay his debt, and he is conversely responsible for everyone else'. James Furner then argues: 'If x = a disadvantage, and y = action to redress that disadvantage, the principle of solidarity is: if any member of a group acquires x, each member has a duty to perform y (if they can assist). All we then need to add, to get to the fundamental principle of developed communism, is to assume that non-satisfaction of a need is a disadvantage. The corresponding principle of solidarity in respect of need says: