Economics is the social science that studies the production, distribution, and consumption of goods and services. Areas of economics may be divided or classified in various ways, including: microeconomics and macroeconomics positive economics and normative economics mainstream economics and heterodox economics Areas of economics may be divided or classified in various ways; however, an economy is usually analyzed in either of two ways: Microeconomics examines the economic behavior of individual units (including businesses and households) and their interactions through individual markets, given scarcity and government regulation. Within microeconomics, general equilibrium theory aggregates across all markets, including their movements and interactions toward equilibrium. Macroeconomics examines an economy as a whole "top down" with a view to understanding interactions between the broadest aggregates such as national income and output, employment and inflation and broad aggregates like total consumption and investment spending and their components. Financial economics has traditionally been considered a part of economics, as its body of results emerges naturally from microeconomics. However, today Finance effectively established itself as a separate, though closely related, discipline. Economics can also be divided into numerous sub disciplines including: international economics, development economics, labor economics, environmental economics, industrial organization, public finance, economic psychology, economic sociology, institutional economics, economic geography, information economics and economics of security.