Re: [R] SystemFit

2009-07-29 Thread Ferdogan
Ferdogan wrote: > > Hi, > > I have two products which are substitudes. I try to fix a system as below > to mydata. > > Demand1 = A1 -B1*Price1 + C1*Price2 > Demand2 = A2 +B2*Price1 - C2*Price2 > > I would expect C1 & B2 to be symmetric, If they are truly su

[R] SystemFit

2009-07-23 Thread Ferdogan
Hi, I have two products which are substitudes. I try to fix a system as below to mydata. Demand1 = A1 -B1*Price1 + C1*Price2 Demand2 = A2 +B2*Price1 - C2*Price2 I would expect C1 & B2 to be symmetric, If they are truly substitude. How can I enforce this symmetry when creating a system of equat

[R] Preserving Symmetry Between Two Equations

2009-07-21 Thread Ferdogan
Hi, I have two products which are substitudes. I try to fix a system as below to mydata. Demand1 = A1 -B1*Price1 + C1*Price2 Demand2 = A2 +B2*Price1 - C2*Price2 I would expect C1 & B2 to be symmetric, If they are truly substitude. How can I enforce this symmetry when creating a system of equat