Technically it can be defined as recognition that [[demand]] is not completely independent of [[supply]]: demand for a good or service often increases if its affordable supply increases. For example, construction of a free highway will result in its increasing use over time. | Technically it can be defined as recognition that [[demand]] is not completely independent of [[supply]]: demand for a good or service often increases if its affordable supply increases. For example, construction of a free highway will result in its increasing use over time. |