In the social sciences, economics is the study of human choice behavior and the methodology used in making production decisions; in particular, though not limited to, how those choices and decisions determine the allocation of scarce resources and their effect on production, distribution, and consumption. Economics studies how individuals and societies seek to satisfy needs and wants through incentives, choices, and allocations within a given set of resource constraints. Alfred Marshall in the late 19th century informally described economics as "the study of man in the ordinary business of life." The word "economics" is from the Greek words οἶκος [oikos], meaning "family, household, estate," and νόμος [nomos], or "custom, law," and hence literally means "household management" or "management of the state." An economist is a person using economic concepts and data in the course of employment, or someone who has earned a university degree in the subject.