In this unit, we learned to apply the price elasticity of demand and price elasticity of supply in the economic decision-making process, examine the impacts of various forms of elasticities on business revenues and marketing strategies, analyze market failures and government failures in the economy, and differentiate how positive and negative externalities cause under- and over-allocation of resources and economic inefficiency.

Let's extend the discussion by examining the practical implications of these concepts. The income elasticities of demand for mobile phones have been estimated to be +0.31. Interpret this coefficient.