<P> According to convention, the demand curve is drawn with price on the vertical (y) axis and quantity on the horizontal (x) axis . The function actually plotted is the inverse demand function . </P> <P> The demand curve usually slopes downwards from left to right; that is, it has a negative association . The negative slope is often referred to as the "((law of demand))", which means people will buy more of a service, product, or resource as its price falls . The demand curve is related to the marginal utility curve, since the price one is willing to pay depends on the utility . However, the demand directly depends on the income of an individual while the utility does not . Thus it may change indirectly due to change in demand for other commodities . </P> <P> However, with Veblen goods, such as status symbols, the utility value of the good is largely the price and demand is higher at higher prices and the demand curve may curve upwards . With a Giffen good the price is taken by the market as a signal of quality, irrespective of the true nature of the product, and hence demand may be very low when priced low and increase at higher price points . </P> <P> The demand curve is often graphed as a straight line of the form Q = a − bP where a and b are parameters . The constant "a" embodies the effects of all factors other than price that affect demand . If income were to change, for example, the effect of the change would be represented by a change in the value of "a" and be reflected graphically as a shift of the demand curve . The constant "b" is the slope of the demand curve and shows how the price of the good affects the quantity demanded . </P>

Does a change in the number of consumers shift the demand curve