$Report variables

Problems with syntax of GAMS
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Lemons
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$Report variables

Post by Lemons » 3 months ago

Hi everyone,

I am very new to GAMs and I am just finding my way around:

I want to add variables to model to report the quantity of goods that the economy imports and exports. This is the inputs used in export production functions, and outputs from import production functions. My code is

Code: Select all

$TITLE A 2-good, 2-factor small open economy model

$ONTEXT
The model os calibrated to the social accounting matrix below

             |   X        Y        W    |   CONS
---------------------------------------------------------
        PX   | 100              -100    |
        PY   |          100     -100    |
        PW   |                   200    |   -200
        PL   | -25      -75             |    100
        PK   | -75      -25             |    100
---------------------------------------------------------
$OFFTEXT

*	Include a scalar to scale labour endowments and define a parameter to report output 
Scalar		LMULT		 Labour endowment multiplier/1/;
Parameter	Output(*,*)	 Production by good and scenario;	
Parameter	Consumption(*,*) Consumption by good and scenario;
Parameter	NetExports(*,*)	 Value of net exports by scenario;
Parameter	Quantity(*,*)	 net exports by scenario;

SCALAR          PW1     Export price of good 1 /1/
		PW2     Export price of good 2 /1/
                trade	Trade flag	/0/;

$ONTEXT
$MODEL:mymodel

$SECTORS:
        X1           ! Production index for good 1
        X2           ! Production index for good 2      
	W            ! Welfare index
	M1$trade     ! Imports of good 1
	M2$trade     ! Imports of good 2
	E1$trade     ! Exports of good 1
	E2$trade     ! Exports of good 2

$COMMODITIES:
        P1           ! Price index for good 1
        P2           ! Price index for good 2 
        PFX$trade    ! Price of foreign exchange	
	PL           ! Price index for primary factor L
        PK           ! Price index for primary factor K
        PW           ! Price index for welfare 

$CONSUMERS:
        HH           ! Household income and expenditure

*	Production
$PROD:X1 s:1          
        O:P1         Q:100
        I:PL         Q:25           
	I:PK         Q:75    

$PROD:X2 s:1
        O:P2         Q:100
        I:PL         Q:75
        I:PK         Q:25   

*	Imports and exports
$PROD:M1$trade 
        O:P1         Q:1
        I:PFX        Q:PW1

$PROD:M2$trade 
        O:P2         Q:1
        I:PFX        Q:PW2

$PROD:E1$trade 
        O:PFX        Q:PW1
        I:P1         Q:1

$PROD:E2$trade 
        O:PFX        Q:PW2
        I:P2         Q:1

$PROD:W s:1
        O:PW         Q:200
        I:P1         Q:100   
        I:P2         Q:100  

$DEMAND:HH
        D:PW         Q:200
        E:PL         Q:(100*LMULT)
        E:PK         Q:100

$REPORT:
	V:OUT1	O:P1	PROD:X1
	V:OUT2	O:P2	PROD:X2
	V:D1	I:P1	PROD:W
	V:D2	I:P2	PROD:W

$OFFTEXT

$SYSINCLUDE mpsgeset mymodel

*	Set a numeraire
P2.FX = 1;

*	Check the benchmark

mymodel.iterlim = 0;
$INCLUDE mymodel.GEN
SOLVE mymodel USING MCP;

mymodel.iterlim = 1000;
$INCLUDE mymodel.GEN
SOLVE mymodel USING MCP;

*	Record the benchmark values
Output("X1","Benchmark") = OUT1.L;
Output("X2","Benchmark") = OUT2.L;

Consumption("X1","Benchmark") = D1.L;
Consumption("X2","Benchmark") = D2.L;

*	Allow the nation to trade with a world price of good 1 10% above the autarky price  
trade = 1;
PW1 = 1.1;

$INCLUDE mymodel.GEN
SOLVE mymodel USING MCP;

* Record the new values of report Variables

Output("X1","P1 = 1.1") = OUT1.L;
Output("X2","P1 = 1.1") = OUT2.L;

Consumption("X1","P1 = 1.1") = D1.L;
Consumption("X2","P1 = 1.1") = D2.L;

NetExports("X1","P1.L = 1.1") = (OUT1.L - D1.L)*P1.L;
NetExports("X2","P1.L = 1.1") = (OUT2.L - D2.L)*P2.L;

Quantity("X1","P1.L = 1.1") = (OUT1.L - D1.L);
Quantity("X2","P1.L = 1.1") = (OUT2.L - D2.L);


Display Output, Consumption, NetExports, Quantity;
The output looks weird though.

---- 935 PARAMETER Quantity net exports by scenario

P1.L = 1.1

X1 18.202
X2 -20.023

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