system of equations
Posted: Mon Apr 26, 2010 2:41 am
I have a data serie “xt” and I am trying to estimate a system of equations on the back of that (a heterogeneous agent model). The model consists of 4 equations of which 3 are (non-observed) endogenous / based on lagged values of xt. The system reads:
xt – xt-1 = c(1) - (1 + mt-1) * c(2) * xt-1 + (1 - mt-1) * c(3) * (xt-1 - yt-1) + εt-1 * √(St-1)
yt = c(4) * yt-1 + (1 – c(4))*xt
St = c(5) + c(6) * St-1 + c(7) * [εt-1 * √(St-1) ] ^2
mt = tanh [(xt – xt-1) * (-c(8) * xt-1 – c(9) *(xt-1 – yt-1))]
so yt, St and mt are not observed, but are actually based on lagged values of xt, the error term from equation 1 and (in another model) based on some of the variables of the first equation. Unfortunately I cannot collapse the system into one “reduced form” equation that thereafter I could estimate. So I tried to enter the four equations in a “new object”- “system” window EViews indicates that “Y” has not been defined.
Does anyone know if it is possible to have the entire system solved (either iteratively or as one system by QML or so)? And if so, how should I then enter it into EViews?
Thanks, Meint
xt – xt-1 = c(1) - (1 + mt-1) * c(2) * xt-1 + (1 - mt-1) * c(3) * (xt-1 - yt-1) + εt-1 * √(St-1)
yt = c(4) * yt-1 + (1 – c(4))*xt
St = c(5) + c(6) * St-1 + c(7) * [εt-1 * √(St-1) ] ^2
mt = tanh [(xt – xt-1) * (-c(8) * xt-1 – c(9) *(xt-1 – yt-1))]
so yt, St and mt are not observed, but are actually based on lagged values of xt, the error term from equation 1 and (in another model) based on some of the variables of the first equation. Unfortunately I cannot collapse the system into one “reduced form” equation that thereafter I could estimate. So I tried to enter the four equations in a “new object”- “system” window EViews indicates that “Y” has not been defined.
Does anyone know if it is possible to have the entire system solved (either iteratively or as one system by QML or so)? And if so, how should I then enter it into EViews?
Thanks, Meint