Shadow Prices in Linear Programming Problems.

In linear programming problems the shadow price of a constraint is the difference between the optimised value of the objective function and the value of the ojective function, evaluated at the optional basis, when the right hand side (RHS) of a constraint is increased by one unit. It may be shown, using the approach of Winston (1995, pp250- 255, 293-300) that the shadow prices corresponding to the constraints of a primal LP problem are equal to the optimal values of teh dual variables.