Neoclassical Preferences 1.U is continuous and twice differentiable 2.U.(c,z)>0>U(c,z) U(c,z)>0>U(c,z) Ui<UoU= 3. limU.=limU.=0, c→0 z→0 limU。=limU.=0. C-→00 2→2 电子科大经管学院马捷 5 元元元元元Neoclassical Preferences 电子科大经管学院 马捷 5 lim lim 0. 3. lim lim , ( , ) 0 ( , ) 2. ( , ) 0 ( , ) 1. U is continuous and twice differentiable. 0 0 2                z z z c c z z c c cz cc zz z zz c cc U U U U U U U U c z U c z U c z U c z