Modelling Issue with Trade

[Antti-L]

Is there any constraint in TIMES that prevents it to achieve a negative objective function?

Yes, and likely that's the problem here. See:  http://forum.kanors-emr.org/showthread.php?tid=368

To quickly add the UC_RHS parameter, you could add the following line into the RUN file, before the call for maindrv.mod:

SET UC_N / OBJVAR /; PARAMETER UC_RHS / OBJVAR.N -1 /;

But you can do it also within the ANSWER shell.