when economist use the term laissez-faire what economic idea are they referring to
Laissez-faire Laissez-faire (/ˌlɛseɪˈfɛər/; French: [lɛsefɛʁ] ( listen); from French: laissez faire, lit. 'let do') is an economic system in which transactions between private parties are free from government intervention such as regulation, privileges, tariffs, and subsidies. The phrase laissez-faire is part of a larger French phrase and basically translates to "let (it/them) do", but in this context usually means to "let go".[1]
Marginal utility Carl Menger presented the theory in Grundsätze der Volkswirtschaftslehre (translated as Principles of Economics) in 1871. Menger's presentation is peculiarly notable on two points. First, he took special pains to explain why individuals should be expected to rank possible uses and then to use marginal utility to decide amongst trade-offs. (For this reason, Menger and his followers are sometimes called “the Psychological School”, though they are more frequently known as “the Austrian School” or as “the Vienna School”.) Second, while his illustrative examples present utility as quantified, his essential assumptions do not.[11] (Menger in fact crossed-out the numerical tables in his own copy of the published Grundsätze.[39]) Menger also developed the law of diminishing marginal utility.[14] Menger's work found a significant and appreciative audience.