What is the definition of elasticity of demand?

Answer 1

Demand elasticities refer to the response among consumers of a good to a change in the good's price. "Elastic" demand means that a small increase in price will lead to a relatively large decrease in demand (or vice versa). Goods with elastic demand curves tend to have many close substitutes. For example, demand for "tangerines" is more elastic than demand for "citrus fruits," because if the price of tangerines rises, you can switch to Oranges etc. Likewise, the demand for "citrus fruits" is more elastic than the demand for "fruit," because if all citrus fruits rise in price, you can switch to apples, bananas, etc, but if the price of all fruits goes up, you're not likely to buy a leg of lamb instead.

Items that are highly "inelastic" may be things that represent small portions of a consumer's budget. If salt goes from $.69 to $3, that is a huge increase in price. But will you stop buying salt? Highly unlikely, because it still represents a small portion of your income, and there are few if any less expensive substitutes. You might not even notice.

Answer 2

Elasticity demand is an economic measure of elasticity of quantity goods or services wanted by consumers and a change made in its price.