Back to Nordhaus DICE versus CJL DICE
Comments: we let
1: s be free
2: delete Nordhaus’ terminal condition on k and investment
3: let investment negative but keep end-of-period k nonnegative
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modification:
1. cancel terminal condition for capital
2. cancel fixed saving rate
3. replace I > 0 by I > -(1-depreciation rate)*K
DICE delta version 8
July 17, 2008.
This version is used for the DICE book, A Question of Balance (YUP, 2008).
We have included only the base, Hotelling, and optimal runs.
Exclude statements are removed so that it can run as a self-contained program.
Created September 5, 2008.
Note that this can be loaded into a data reading program,
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SETS T Time periods /1*60/ ;
SCALARS
** Preferences
B_ELASMU Elasticity of marginal utility of consumption / 2.0 /
B_PRSTP Initial rate of social time preference per year / .015 /
** Population and technology
POP0 2005 world population millions /6514 /
GPOP0 Growth rate of population per decade /.35 /
POPASYM Asymptotic population / 8600 /
A0 Initial level of total factor productivity /.02722 /
GA0 Initial growth rate for technology per decade /.092 /
DELA Decline rate of technol change per decade /.001 /
DK Depreciation rate on capital per year /.100 /
GAMA Capital elasticity in production function /.300 /
Q0 2005 world gross output trill 2005 US dollars /61.1 /
K0 2005 value capital trill 2005 US dollars /137. /
** Emissions
SIG0 CO2-equivalent emissions-GNP ratio 2005 /.13418 /
GSIGMA Initial growth of sigma per decade /-.0730 /
DSIG Decline rate of decarbonization per decade /.003 /
DSIG2 Quadratic term in decarbonization / .000 /
ELAND0 Carbon emissions from land 2005(GtC per decade) / 11.000 /
** Carbon cycle
MAT2000 Concentration in atmosphere 2005 (GtC) /808.9 /
MU2000 Concentration in upper strata 2005 (GtC) /1255 /
ML2000 Concentration in lower strata 2005 (GtC) /18365 /
b11 Carbon cycle transition matrix /0.810712 /
b12 Carbon cycle transition matrix /0.189288 /
b21 Carbon cycle transition matrix /0.097213 /
b22 Carbon cycle transition matrix /0.852787 /
b23 Carbon cycle transition matrix /0.05 /
b32 Carbon cycle transition matrix /0.003119 /
b33 Carbon cycle transition matrix /0.996881 /
** Climate model
T2XCO2 Equilibrium temp impact of CO2 doubling oC / 3 /
FEX0 Estimate of 2000 forcings of non-CO2 GHG / -.06 /
FEX1 Estimate of 2100 forcings of non-CO2 GHG / 0.30 /
TOCEAN0 2000 lower strat. temp change (C) from 1900 /.0068 /
TATM0 2000 atmospheric temp change (C)from 1900 /.7307 /
C1 Climate-equation coefficient for upper level /.220 /
C3 Transfer coeffic upper to lower stratum /.300 /
C4 Transfer coeffic for lower level /.050 /
FCO22X Estimated forcings of equilibrium co2 doubling /3.8 /
** Climate damage parameters calibrated for quadratic at 2.5 C for 2105
A1 Damage intercept / 0.00000 /
A2 Damage quadratic term / 0.0028388 /
A3 Damage exponent / 2.00 /
** Abatement cost
EXPCOST2 Exponent of control cost function /2.8 /
PBACK Cost of backstop 2005 000$ per tC 2005 /1.17 /
BACKRAT Ratio initial to final backstop cost / 2 /
GBACK Initial cost decline backstop pc per decade /.05 /
LIMMIU Upper limit on control rate / 1 /
** Participation
PARTFRACT1 Fraction of emissions under control regime 2005 /1 /
PARTFRACT2 Fraction of emissions under control regime 2015 /1 /
PARTFRACT21 Fraction of emissions under control regime 2205 /1 /
DPARTFRACT Decline rate of participation /0 /
** Availability of fossil fuels
FOSSLIM Maximum cumulative extraction fossil fuels / 6000 /
** Scaling and inessential parameters
scale1 Scaling coefficient in the objective function /194 /
scale2 Scaling coefficient in the objective function /381800 / ;
* Definitions for outputs of no economic interest
SETS
TFIRST(T)
TLAST(T)
TEARLY(T)
TLATE(T);
PARAMETERS
L(T) Level of population and labor
AL(T) Level of total factor productivity
SIGMA(T) CO2-equivalent-emissions output ratio
R(T) Instantaeous rate of social time preference
RR(T) Average utility social discount rate
GA(T) Growth rate of productivity from 0 to T
FORCOTH(T) Exogenous forcing for other greenhouse gases
GL(T) Growth rate of labor 0 to T
GCOST1 Growth of cost factor
GSIG(T) Cumulative improvement of energy efficiency
ETREE(T) Emissions from deforestation
COST1(t) Adjusted cost for backstop
PARTFRACT(T) Fraction of emissions in control regime
AA1 Variable A1
AA2 Variable A2
AA3 Variable A3
ELASMU Variable elasticity of marginal utility of consumption
PRSTP Variable nitial rate of social time preference per year
LAM Climate model parameter
Gfacpop(T) Growth factor population ;
PARAMETERS
L(T) Level of population and labor
AL(T) Level of total factor productivity
SIGMA(T) CO2-equivalent-emissions output ratio
RR(T) Average utility social discount factor
GA(T) Growth rate of productivity from 0 to T
FORCOTH(T) Exogenous forcing for other greenhouse gases
GL(T) Growth rate of labor 0 to T
GCOST1 Growth of cost factor
GSIG(T) Cumulative improvement of energy efficiency
ETREE(T) Emissions from deforestation
COST1(t) Adjusted cost for backstop
PARTFRACT(T) Fraction of emissions in control regime
AA1 Variable A1
AA2 Variable A2
AA3 Variable A3
ELASMU Variable elasticity of marginal utility of consumption
PRSTP Variable nitial rate of social time preference per year
LAM Climate model parameter
Gfacpop(T) Growth factor population ;
* Unimportant definitions to reset runs
TFIRST(T) = YES$(ORD(T) EQ 1);
TLAST(T) = YES$(ORD(T) EQ CARD(T));
TEARLY(T) = YES$(ORD(T) LE 20);
TLATE(T) = YES$(ORD(T) GE 21);
AA1 = A1;
AA2 = A2;
AA3 = A3;
ELASMU = B_ELASMU;
PRSTP = B_PRSTP;
b11 = 1 – b12;
b21 = 587.473*B12/1143.894;
b22 = 1 – b21 – b23;
b32 = 1143.894*b23/18340;
b33 = 1 – b32 ;
* Important parameters for the model
LAM = FCO22X/ T2XCO2;
Gfacpop(T) = (exp(gpop0*(ORD(T)-1))-1)/exp(gpop0*(ORD(T)-1));
L(T)=POP0* (1- Gfacpop(T))+Gfacpop(T)*popasym;
ga(T)=ga0*EXP(-dela*10*(ORD(T)-1));
al(“1”) = a0;
LOOP(T, al(T+1)=al(T)/((1-ga(T))););
gsig(T)=gsigma*EXP(-dsig*10*(ORD(T)-1)-dsig2*10*((ord(t)-1)**2));sigma(“1”)=sig0;LOOP(T,sigma(T+1)=(sigma(T)/((1-gsig(T+1)))););
cost1(T) = (PBACK*SIGMA(T)/EXPCOST2)* ( (BACKRAT-1+ EXP (-gback* (ORD(T)-1) ) )/BACKRAT);
ETREE(T) = ELAND0*(1-0.1)**(ord(T)-1);
RR(t)=1/((1+prstp)**(10*(ord(T)-1)));
FORCOTH(T)= FEX0+ .1*(FEX1-FEX0)*(ORD(T)-1)$(ORD(T) LT 12)+ 0.36$(ORD(T) GE 12);
partfract(t) = partfract21;
PARTFRACT(T)$(ord(T)<25) = Partfract21 + (PARTFRACT2-Partfract21)*exp(-DPARTFRACT*(ORD(T)-2));
partfract(“1”)= PARTFRACT1;
VARIABLES
MIU(T) Emission control rate GHGs
FORC(T) Radiative forcing in watts per m2
TATM(T) Temperature of atmosphere in degrees C
TOCEAN(T) Temperatureof lower oceans degrees C
MAT(T) Carbon concentration in atmosphere GtC
MATAV(T) Average concentrations
MU(T) Carbon concentration in shallow oceans Gtc
ML(T) Carbon concentration in lower oceans GtC
E(T) CO2-equivalent emissions GtC
C(T) Consumption trillions US dollars
K(T) Capital stock trillions US dollars
CPC(T) Per capita consumption thousands US dollars
PCY(t) Per capita income thousands US dollars
I(T) Investment trillions US dollars
S(T) Gross savings rate as fraction of gross world product
RI(T) Real interest rate per annum
Y(T) Gross world product net of abatement and damages
YGROSS(T) Gross world product GROSS of abatement and damages
YNET(T) Output net of damages equation
DAMAGES(T) Damages
ABATECOST(T) Cost of emissions reductions
CCA(T) Cumulative industrial carbon emissions GTC
PERIODU(t) One period utility function
UTILITY;
*POSITIVE VARIABLES MIU, TATM, TOCE, E, MAT, MATAV, MU, ML, Y, YGROSS, C, K, I, CCA ;
POSITIVE VARIABLES MIU, TATM, TOCE, E, MAT, MATAV, MU, ML, Y, YGROSS, C, K, CCA ;
EQUATIONS
CCTFIRST(T) First period cumulative carbon
CCACCA(T) Cumulative carbon emissions
UTIL Objective function
YY(T) Output net equation
YNETEQ(T) Output net of damages equation
YGROSSEQ(T) Output gross equation
DAMEQ(T) Damage equation
ABATEEQ(T) Cost of emissions reductions equation
CC(T) Consumption equation
KK(T) Capital balance equation
KK0(T) Initial condition for capital
* KC(T) Terminal condition for capital
InvestCond(T) investment condition
CPCE(t) Per capita consumption definition
PCYE(T) Per capita income definition
EE(T) Emissions equation
SEQ(T) Savings rate equation
RIEQ(T) Interest rate equation
FORCE(T) Radiative forcing equation
MMAT0(T) Starting atmospheric concentration
MMAT(T) Atmospheric concentration equation
MMATAVEQ(t) Average concentrations equation
MMU0(T) Initial shallow ocean concentration
MMU(T) Shallow ocean concentration
MML0(T) Initial lower ocean concentration
MML(T) Lower ocean concentration
TATMEQ(T) Temperature-climate equation for atmosphere
TATM0EQ(T) Initial condition for atmospheric temperature
TOCEANEQ(T) Temperature-climate equation for lower oceans
TOCEAN0EQ(T) Initial condition for lower ocean temperature
PERIODUEQ(t) Instantaneous utility function equation ;
** Equations of the model
CCTFIRST(TFIRST).. CCA(TFIRST)=E=0;
CCACCA(T+1).. CCA(T+1)=E=CCA(T)+ E(T);
KK(T).. K(T+1) =L= (1-DK)**10 *K(T)+10*I(T);
KK0(TFIRST).. K(TFIRST) =E= K0;
*KC(TLAST).. .02*K(TLAST) =L= I(TLAST);
InvestCond(TLAST).. (1-DK)**10 *K(TLAST)+10*I(TLAST) =G= 0;
EE(T).. E(T)=E=10*SIGMA(T)*(1-MIU(T))*AL(T)*L(T)**(1-GAMA)*K(T)**GAMA + ETREE(T);
FORCE(T).. FORC(T) =E= FCO22X*((log((Matav(T)+.000001)/596.4)/log(2)))+FORCOTH(T);
MMAT0(TFIRST).. MAT(TFIRST) =E= MAT2000;
MMU0(TFIRST).. MU(TFIRST) =E= MU2000;
MML0(TFIRST).. ML(TFIRST) =E= ML2000;
MMAT(T+1).. MAT(T+1) =E= MAT(T)*b11+MU(T)*b21 + E(T);
MMATAVEQ(t).. MATAV(T) =e= (MAT(T)+MAT(T+1))/2 ;
MML(T+1).. ML(T+1) =E= ML(T)*b33+b23*MU(T);
MMU(T+1).. MU(T+1) =E= MAT(T)*b12+MU(T)*b22+ML(T)*b32;
TATM0EQ(TFIRST).. TATM(TFIRST) =E= TATM0;
TATMEQ(T+1).. TATM(T+1) =E= TATM(t)+C1*(FORC(t+1)-LAM*TATM(t)-C3*(TATM(t)-TOCEAN(t)));
TOCEAN0EQ(TFIRST).. TOCEAN(TFIRST) =E= TOCEAN0;
TOCEANEQ(T+1).. TOCEAN(T+1) =E= TOCEAN(T)+C4*(TATM(T)-TOCEAN(T));
YGROSSEQ(T).. YGROSS(T) =e= AL(T)*L(T)**(1-GAMA)*K(T)**GAMA;
DAMEQ(T).. DAMAGES(t) =E= YGROSS(T)- YGROSS(T)/(1+aa1*TATM(T)+ aa2*TATM(T)**aa3);
YNETEQ(T).. YNET(T) =E= YGROSS(T)/(1+aa1*TATM(T)+ aa2*TATM(T)**aa3);
ABATEEQ(T).. ABATECOST(T) =E= (PARTFRACT(T)**(1-expcost2))*YGROSS(T)*(cost1(t)*(MIU(T)**EXPcost2));
YY(T).. Y(T) =E= YGROSS(T)*((1-(PARTFRACT(T)**(1-expcost2))*cost1(t)*(MIU(T)**EXPcost2)))/(1+aa1*TATM(T)+ aa2*TATM(T)**aa3);
SEQ(T).. S(T) =E= I(T)/(.001+Y(T));
RIEQ(T).. RI(T) =E= GAMA*Y(T)/K(T)- (1-(1-DK)**10)/10 ;
CC(T).. C(T) =E= Y(T)-I(T);
CPCE(T).. CPC(T) =E= C(T)*1000/L(T);
PCYE(T).. PCY(T) =E= Y(T)*1000/L(T);
PERIODUEQ(T).. PERIODU(T) =E= ((C(T)/L(T))**(1-ELASMU)-1)/(1-ELASMU);
UTIL.. UTILITY =E= SUM(T, 10 *RR(T)*L(T)*(PERIODU(T))/scale1)+ scale2 ;
** Upper and Lower Bounds: General conditions for stability
K.lo(T) = 100;
MAT.lo(T) = 10;
MU.lo(t) = 100;
ML.lo(t) = 1000;
C.lo(T) = 20;
TOCEAN.up(T) = 20;
TOCEAN.lo(T) = -1;
TATM.up(t) = 20;
miu.up(t) = LIMMIU;
partfract(“1”)= 0.25372;
* First period predetermined by Kyoto Protocol
miu.fx(“1”) = 0.005;
** Fix savings assumption for standardization if needed
*s.fx(t)=.22;
** Cumulative limits on carbon use at 6000 GtC
CCA.up(T) = FOSSLIM;
** Solution options
option iterlim = 99900;
option reslim = 99999;
option solprint = on;
option limrow = 0;
option limcol = 0;
model CO2 /all/;
* Optimal run
* Solution for optimal run
solve CO2 maximizing UTILITY using nlp ;
solve CO2 maximizing UTILITY using nlp ;
solve CO2 maximizing UTILITY using nlp ;
solve CO2 maximizing UTILITY using nlp ;
solve CO2 maximizing UTILITY using nlp ;
solve CO2 maximizing UTILITY using nlp ;