# ECO – determine the Price-Elasticity of Demand Coefficient

Column I – determine the Price-Elasticity of Demand Coefficient. Refer to the Price-ElasticityCoefficient and Formula :change in quantity demandedEP = —————————————sum of quantities demanded / 2change in price?—————————sum of prices / 2The data in the first four columns represent price (P) and quantity demanded (Qd) in time 1 (beforechange in price) and time 2 (after change in price) for a specific good. Note that results should beexpressed in absolute terms. For example, -1 should be expressed as ?1?, as should a positive 1.Column II â Interpret the results and indicate the type of elasticity which applies (such as Elastic,Inelastic, Perfectly Elastic, Perfectly Inelastic, Unitary) based on how the quantity demanded changedsubsequent to a change in price.Column III â Determine if the good in question would be considered a necessity, a luxury or neither.Column IV â Indicate, in monetary terms, how much is the change in total revenue or totalexpenditure (TR = P X QD), from the first price level to the second.Column V – indicate the direction of the change, that is, increasing or decreasing (show a + signfor increasing and a â sign for decreasing).Note: for any monetary result please include the applicable currency symbol (\$, â¬, etc.)