2. Reciprocal model Y Bo+BX+B,X,+8 3. Double-log constant elasticity)model Iny=a+BinX+& ote dyx dIny Elasticity dx y dInx B(const) 2021/2/202021/2/20 3 2. Reciprocal model: 3. Double-log(constant elasticity) model: 0 1 1 2 2 1 Y     X X = + + + ln ln Y X = + +    ln Elasticity (const.) ln dY X d Y dX Y d X = = =  Note :