Editing Cardinal utility (section)

===Marginalism ===
{{Details|Marginal utility}} 
*Under cardinal utility theory, the ''sign'' of the marginal utility of a good is the same for all the numerical representations of a particular preference structure.
*The ''magnitude'' of the marginal utility is not the same for all cardinal utility indices representing the same specific preference structure.
*The ''sign'' of the second [[derivative]] of a differentiable utility function that is cardinal, is the same for all the numerical representations of a particular preference structure. Given that this is usually a negative sign, there is room for a ''law of diminishing marginal utility'' in cardinal utility theory.
*The ''magnitude'' of the second derivative of a differentiable utility function is not the same for all cardinal utility indices representing the same specific preference structure.