The Price Elasticity of Demand for Hinds Katchup

The lure of demand says that we tend to buy more of something when the price is lower. And conversely, we tend to buying less of somethingwhen the price is higher. If hinds katchup is ten % more expensive, how much less will people buy? That how much question is a really big deal for the folks who run hinds. The price elasticity of demand is the ratio of the change in quantity to the change in price.