The demand curve is one of the fundamental concepts of economics. It illustrates the relationship between the price of a good or service and the demand for that product, that is, the way a change in ...

A linear demand curve is a line representing the relationship between the demand for a product or service and its price. Everyone knows that sales are proportional to price: The more you charge for an ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Robert Kelly is managing director of XTS ...

Sean Ross is a strategic adviser at 1031x.com, Investopedia contributor, and the founder and manager of Free Lances Ltd. Robert Kelly is managing director of XTS Energy LLC, and has more than three ...