An autarky is an economy that does no trade with the outside world, or an ecosystem not affected by influences from its outside, and relies entirely on its own resources. In the economic meaning, it is also referred to as a "closed economy."
The word "autarky" is from the Greek αὐτάρκεια, which means "self-sufficiency" (derived from αὐτο, "self," and ἀρκέω, "to suffice"). It is sometimes confused with autarchy (Greek: αὐταρχία), which either means self-government or government by absolute rule. ("Autarchy" is sometimes also used as a variant spelling of "autarky").
Today, economical autarkies are found very rarely. An example of a current autarky is North Korea, based on the government ideology of Juche (self-reliance). However, even North Korea as a small amount of trade between China and Japan.
Pre-modern economies (those existing before the industrial revolution) are more difficult to analyze by today's standards, but a number of them, particularly those of hydraulic empires, may be seen as having been centrally planned as well.
There is a Trotskyist theory of the permanent arms economy, put forward by Michael Kidron, which leads on from the contention that war and accompanying industrialisation is a continuing feature of capitalist states and that central planning and other features of the war economy are ever present.
A palace economy may be considered as a subsistence economy augmented with elements of command economy.
In economics, the term informal economy refers to the general market income category (or sector) wherin certain types of income and the means of their generation are “unregulated by the institutions of society, in a legal and social environment in which similar activities are regulated.” (Portes et al.)
Although the informal economy is often associated with developing countries —where up to 60% of the labor force works, all economic systems contain an informal economy in some proportion.
Governments have tried to regulate (formalize) aspects of their economies for as long as surplus wealth has existed which is at least as early as Sumer.