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]
Externality Two British economists are credited with having initiated the formal study of externalities, or "spillover effects": Henry Sidgwick (1838–1900) is credited with first articulating, and Arthur C. Pigou (1877–1959) is credited with formalizing the concept of externalities.[5]