They're often valuable for vastly different reasons â like the World War II-era coins minted from atypical metals, or double-printed pennies â but each one is easy to miss if you're not paying attention. See also: Californian Couple Finds $10 Million Worth of Gold Coins in Tin Can.
A subsistence economy is a non-monetary economy which relies on natural resources to provide for basic needs, through hunting, gathering, and subsistence agriculture.
Intensive Agriculture. Intensive agriculture is the primary subsistence pattern of large-scale, populous societies. It results in much more food being produced per acre compared to other subsistence patterns.he first intensive agricultural societies were the ancient civilizations in Egypt, Mesopotamia (now Iraq and eastern Syria), India and Pakistan, North China, Mesoamerica, and Western South America.