Multivariate Regression Estimation

[masroorzaidi]

I am working with multivariate regression model having 9 equations each as follows
d(y) d(X1) d(X2) d(X3)
where Y is the exports of ith group and i goes from 1-9 and x1=gdp of partner country x2=Exchange Rate x3= net protfolio investment in the home country.
After making my variables stationary I estimated these 9 equations using SUR estimation... all independent variables are signifcant but i am having a negative value of R-Square for most of the equations. I know when using SUR we don't give much importance to R-Square value and give more importance to likelihood statistic but i am unable to see likelihood value in my results. Need help

[startz]

Perhaps you need constant terms?