The basic concept of elasticity is:

How sensitive are changes in the quantity of a good purchased to changes in its priced

How sensitive are changes in output to the health of the economy

How sensitive are changes in the price of a good to changes in the quantity demanded

How sensitive are changes in incomes to changes in output in the economy

Cross elasticity measures:

Whether the quantity demanded is sensitive to the quantity supplied

Whether the quantity demanded for a good is sensitive to price

Whether two goods are substitutes or complements

Whether the quantity supplied for a good is sensitive to price

Elasticity of supply is determined by:

Absolute income levels

The availability of substitute products and absolute income levels

Time

The availability of substitute products

The Income effect describes:

The tendency for individuals to substitute items when income falls

That as prices fall, our real income rises allowing us to purchase more of a particular good.

That we can buy more of all goods when our nominal income rises

That unemployment is inversely related to income