Editing Marshallian demand function (section)

== Revealed preference ==
Marshall's theory suggests that pursuit of utility is a motivational factor to a consumer which can be attained through the consumption of goods or service. The amount of consumer's utility is dependent on the level of consumption of a certain good, which is subject to the fundamental tendency of human nature and it is described as the law of [[diminishing marginal utility]]. 

As utility maximum always exists, Marshallian demand correspondence must be nonempty at every value that corresponds with the standard budget set.