Marginal Values - Binding Constraints

GAMS
1

I wrote a simple LP model. Some of the constraints are binding. I am
supposed to get Marginal Values (or shadow prices) for those binding
constraints. But I do not see any in LP solution. Should I write the
dual to find the shadow values?

Simple LP or NLP gives me shadow values for constraints that are not
binding; there are marginal values for variables that are NOT in the
final solution.

Can you please give me pointers on interpreting marginal values in
GAMS output, and how the marginal values are computed?

Thanks

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2

I think I found the answer for this:

http://agecon2.tamu.edu/people/faculty/mccarl-bruce/641clas/03_641_intro_gams_general.pdf
Page 22.

equation.m gives me the Shadow Prices for binding/non-binding
constraints.
variable.m gives me the Reduced Cost if a non-basic variable is
included.

Please let me know if any of you have additional inputs on this.
Thanks

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