Consider some determinants of the price elasticity of demand: • the availability of close substitutes • whether the good is a necessity or a luxury • how broadly you define the market • the time horizon being considered a good without any close substitutes is likely to have relatively elastic demand, since consumers cannot easily switch to a substitute good if the price of the good rises. a good’s price elasticity of demand depends in part on how necessary it is relative to other goods. if the following goods are priced approximately the same, which one has the least elastic demand