The Rotterdam model can be used to estimate one form of this quantity, for which Richard Stone was the first to empirically derive a linear expenditure system. For a firm in a perfectly competitive market, this quantity is infinitely elastic. (-5[1])The Slutsky equation relates the Marshallian form of this quantity (10[1])to its Hicksian form (-5[1])by accounting for the substitution and income effects. The cross elasticity of this quantity measures (10[1])its sensitivity to changes in a different good’s price. (10[2])For Veblen goods, (10[1])this quantity [emphasize] increases as price (10[1])increases, often due to the value of those goods as status (10[1])symbols. For 10 points, what quantity is defined as consumers’ willingness and (10[1])ability to buy a certain good? (10[1])■END■