This code analyzes the interdependencies between economic sectors in Japan, incorporating environmental extensions. It calculates the total output of each sector required to meet a given final demand, while considering the environmental impacts associated with production processes.
- Sets and Parameters:
Set i 'sector' /S1S20/: Defines a set of 20 sectors, labeled S1 to S20, representing different economic activities. Parameter t(i,): Represents the input-output matrix, where t(i,j) indicates the amount of sector i's output required as input by sector j. It's initially empty and loaded from an external Excel file (JAPANINPUT_V2.xlsx) using GAMS commands. Parameter d(i) /S1*S20 = 100/: Sets a final demand of 100 units for each sector. 2. Variables:
Variable x(i): Represents the total output of sector i. Variable dummy: A dummy variable used for linear programming optimization. 3. Equations:
*Equation e1(i).. x(i) - sum(j, t(i,j)x(j)) =e= d(i): Ensures that the total output of each sector (x(i)) meets its final demand (d(i)), considering intermediate inputs from other sectors (t(i,j)*x(j)). Equation edum.. dummy =e= 0: A placeholder equation for the linear programming model. 4. Model and Solution:
Model m /all/: Creates a model containing all defined sets, parameters, variables, and equations. Solve m using lp minimizing dummy: Solves the linear programming model, minimizing the dummy variable (which has no practical effect) to find a feasible solution for sector outputs (x(i)). 5. Output:
display x.l: Displays the calculated optimal values of sector outputs (x(i)). display d: Displays the final demand values (d(i)) for reference.
The specific environmental extensions incorporated in the model are not explicitly visible in this code snippet and likely reside in the external data file (JAPANINPUT_V2.xlsx). Understanding the structure of the input-output matrix (t(i,j)) and the environmental extensions is crucial for interpreting the results and drawing meaningful conclusions.