where "M" is the consumption of goods other than automobiles, "x" the car's quality and "n" the number of automobiles. Let "Y""i", "D""i" and "S""i" be income, demand and supply for group "i". Assuming that utilities are linear, that the traders are Von Neumann–Morgenstern utility maximizers and that the price of other "M" goods is unitary, the demand "D"1 for cars is "Y"1/"p" if "μ"/"p" > 1, otherwise null. The demand "D"2 is "Y"2/"p" if 3"μ"/"2" > "p", otherwise null. Market demand is given by: