A few useful utility functions to think about (1)Quasi-Linear Preferences, i.e U(x1, x2,.xL=x1+o(x2, ...xL) First order conditions are then pi tor all i >1 This means that consumption of all goods except for good one is independent of income and depends only on prices. Good one just takes up the residual incomeA few useful utility functions to think about: (1) Quasi-Linear Preferences, i.e. Ux1, x2,... xL   x1  x2,... xL  First order conditions are then:  xi  pi for all i  1. This means that consumption of all goods, except for good one is independent of income and depends only on prices. Good one just takes up the residual income