Hi Marie!
On Friday 10 October 2008 12:40:23, Marie Vandresse
wrote:> I would like to estimate a linear expendire with Systemfit package.
> (method: "SUR")
If I remember correctly, the "linear expenditure system" (LES) is
linear in
income but non-linear in the parameters. Hence, you have to estimate a system
of non-linear equations. Unfortunately, the nlsystemfit() function in the
systemfit package that estimates systems of non-linear equations is still
under development and has convergence problems rather often. Since the
systemfit() function in the systemfit package that estimates systems of
linear equations is very reliable [1], I suggest that you choose a demand
system that is linear in parameters (e.g. the Almost Ideal Demand System,
AIDS)
[1] http://www.jstatsoft.org/v23/i04
> As someone could show me how to define the equations?
If you use the aidsEst() function in the micEcon package [2], you don't have
to specify the equations of the Almost Ideal Demand System yourself.
[2] http://www.micEcon.org
Best wishes,
Arne
--
Arne Henningsen
http://www.arne-henningsen.name