NISHIO Hirokazu[Translate]
Cobb-Douglas utility curve
u(x, y) = x^a y^{1-a}
図はa=0.5の時、u(x, y) = x^{0.5} y^{0.5}
これはx,yそれぞれ対数を取れば単なる重み付平均である
つまり、片方の財の効用はその量の対数に比例する、ということ
一方で予算制約線は対数を取らないこの空間上で直線になる
Cobb, C. W., & Douglas, P. H. (1928). A theory of production. The American Economic Review, 18(1), 139-165.


Constant Elasticity of Substitution (CES) utility function
u(x, y) = (a x ^ r + b y ^ r) ^ {1/r}

quadratic
u(x, y) = 2 a x - (b - y)^2

"Engineer's way of creating knowledge" the English version of my book is now available on [Engineer's way of creating knowledge]

(C)NISHIO Hirokazu / Converted from [Scrapbox] at [Edit]