What is the formula for calculating elasticity?

Elasticity is a measure of how much one variable (typically a dependent variable) changes in response to a change in another variable (typically an independent variable). In economics, it is often used to measure how sensitive the quantity demanded or supplied of a good is to changes in price, income, or the price of other goods.

The general formula for calculating elasticity (E) can be expressed as: \( E = \dfrac{\% \text{ change in dependent variable}}{\% \text{ change in independent variable}} \) Or, equivalently: \( E = \dfrac{\text{change in dependent variable} / \text{original dependent variable}}{\text{change in independent variable} / \text{original independent variable}} \) Or, more concisely: \( E = \dfrac{\Delta Y / Y}{\Delta X / X} \) Where: - \(E\) is the elasticity - \(Y\) is the dependent variable (e.g., quantity demanded or supplied) - \(X\) is the independent variable (e.g., price, income, or the price of other goods) - \(\Delta Y\) represents the change in the dependent variable - \(\Delta X\) represents the change in the independent variable

The general formula can be adapted for specific types of elasticity: 1. Price elasticity of demand: \(E_d = \dfrac{\Delta Q_d / Q_d}{\Delta P / P}\) 2. Price elasticity of supply: \(E_s = \dfrac{\Delta Q_s / Q_s}{\Delta P / P }\) 3. Income elasticity of demand: \(E_i = \dfrac{\Delta Q_d / Q_d}{\Delta I / I }\) 4. Cross-price elasticity of demand: \(E_{xy} = \dfrac{\Delta Q_x / Q_x}{\Delta P_y / P_y }\) Where: - \(E_d\) is the price elasticity of demand - \(E_s\) is the price elasticity of supply - \(E_i\) is the income elasticity of demand - \(E_{xy}\) is the cross-price elasticity of demand - \(Q_d\) is the quantity demanded - \(Q_s\) is the quantity supplied - \(P\) is the price level - \(I\) is the income - \(Q_x\) is the quantity demanded of good X - \(P_y\) is the price of another good Y