1. Methodology
  2. Micro-macro linkage
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Linking CGE and microsimulation models: A comparison of different approaches

  1. Giulia Colombo  Is a corresponding author
  1. Department of Economic and Social Science - Catholic University of Milan and SiNSYS NV/SA
Research article
Cite this article as: G. Colombo; 2018; Linking CGE and microsimulation models: A comparison of different approaches; International Journal of Microsimulation; 3(1); 72-91. doi: 10.34196/ijm.00026
2 figures and 21 tables

Figures

The Top-Down approach.
The Top-Down/Bottom-Up approach.

Tables

Table 1
Description of the subscripts for the microsimulation model.
m Households m = 1, 2, …, 24
i Individuals belonging to household m i = 1, …, NCm (NCm: number of components of household m)
q Goods q = 1,2
Table 2
Direct income tax rates.
Household Income Tax rate
Up to 10,000 0%
Up to 15,000 15%
Up to 26,000 24%
Up to 70,000 32%
Over 70,000 39%
Table 3
Heckman selection model, two-step estimates.
Coefficient Std. Error z P>|z|
constant 7.0321 0.3145 22.36 0.000
ln(age) 0.6978 0.0833 8.38 0.000
sex −0.4662 0.1018 −4.58 0.000
qualification 0.3966 0.0772 5.14 0.000
education 0.5250 0.0872 6.02 0.000
Mills ratio 0.2160 0.1473 1.47 0.143
Selection
ln(age) 0.3386 0.0807 4.19 0.000
sex −1.5492 0.2803 −5.53 0.000
qualification 1.0204 0.2729 3.74 0.000
children under 6 0.1682 0.2368 0.71 0.478
region −0.7515 0.2980 −2.52 0.012
rho 0.7628
sigma 0.2832
  1. Notes: Dependent variable: logarithm of wage.

Table 4
Binary logit model of labour status choice.
Coefficient Std. Error z P>|z|
ln(real wage) 0.1972 0.0465 4.25 0.000
sex −1.8948 0.4078 −4.65 0.000
qualification 1.4408 0.4257 3.38 0.001
region −0.7185 0.3295 −2.18 0.029
children under 6 0.2691 0.2973 0.91 0.365
education −0.7633 0.6717 −1.14 0.256
Mean dependent var 0.6647 S.D. dependent var 0.4735
S.E. of regression 0.3767 Akaike info criterion 0.9015
Sum squared resid 23.2688 Schwarz criterion 1.0122
Log likelihood −70.6305 Hannan-Quinn criter. 0.9464
Avg. log likelihood −0.4155
  1. Notes: Dependent Variable: Activity Status.

Table 5
SAM of the economy.
C1 C2 S1 S2 K L H G SI RoW Total
C1 57.5 15.5 95.2 61.2 30.3 23.5 283.3
C2 17.1 23.5 312.8 48.5 14.2 76.5 492.5
S1 283.3 283.3
S2 492.5 492.5
K 72.2 23.0 13.1 108.3
L 83.2 353.8 116.4 553.4
H 108.3 553.4 39.8 701.5
G 12.3 17.7 249.0 279.0
SI 44.5 44.5
RoW 41.0 59.0 100.0
Total 283.3 492.5 283.3 492.5 108.3 553.4 701.5 269.9 44.5 100.0
  1. Notes: Cq: consumption of good q; Sq: production sector q; K: capital account; L: labour account; H: representative household account; G: public sector; SI: savings-investments account, RoW: Rest of the World account.

Table 6
Values of some parameters for the CGE model.
Sector 1 Sector 2
Elasticity of substitution (EOS) in production function (aggregation of capital and labour) 0.7 0.5
Elasticity of substitution for Armington composite good 0.7 1.2
Elasticity of transformation for exports and domestic production delivered to the domestic market −2.0 −3.0
Initial tariff rates on imports 0.3 0.3
Initial time endowment 656.7
Wage elasticity of labour supply (estimated from the household survey) −0.18665
Table 7
Variables and parameters of the CGE model
Variables Parameters
PK Return to capital ty Income tax rate
PL Wage rate tmq Tariff rates on imports
Pq Price of Armington composite good ε_LS Wage elasticity of labour supply
PDq Price of output mps Marginal propensity to save
PDDq Price of domestically produced good delivered to domestic market αHq Cobb-Douglas power of commodity q in RH’s utility function
PWEq World price of exports (foreign currency) αHl Cobb-Douglas power of leisure in RH’s utility function
PWMq World price of imports (foreign currency) αCGq Cobb-Douglas power of commodity q in government utility function
PMq Price of imports (local currency) αKG Cobb-Douglas power of capital in government utility function
PEq Price of exports (local currency) αLG Cobb-Douglas power of labour in government utility function
ER Exchange rate ioqs Technical coefficients
PC Consumer price index aFq Efficiency parameter production function
KS Capital endowment (exogenous) γFq Share parameter in production function
LS Labour supply (endogenous) σFq EOS in firm q’s production function
TS Time endowment (exogenous) aAq Efficiency parameter in Armington function
Xq Domestic sales (Armington composite) γAq Share parameter in Armington function
XDq Domestic production σAq EOS in firm q’s Armington function
XDDq Domestically produced good delivered to domestic market αIq Cobb-Douglas power of commodity q in Bank’s utility function
Mq Imports aTq Efficiency parameter in CET function
Eq Exports γTq Share parameter in CET function
Kq Capital demand by firms σTq Elasticity of transformation in CET function
Lq Labour demand by firms
Iq Investment good
Cq Consumption demand by household
Cl Demand for leisure
Y Household’s income
S Household’s savings
CBUD Household’s consumption expenditure
TF Public transfers to household
TAXREV Tax revenues
CGq Consumption demand by government
KG Capital demand by government
LG Labour demand by government
Table 8
Equations of the CGE model
Description Equations
Demand for consumption goods PqCq=αHqCBUD,where q=1,2
Leisure CI=[ (1ty)PL ]1αHI(1αHI)CBUD
Labour supply LS=TSCI
Savings S=mps(1ty)Y
Consumer price index PC=q=12PqαHq
CES production function XDq=aFq[ γFqKq(σFq1)σFq+(1γFq)Lq(σFq1)σFq ]σFq(σFq1)
CES FOC for capital Kq=XDqaFq(γFqPK)σFq[ γFqσFqPK(1σFq)+(1γFq)σFqPL(1σFq) ]σFq(1σFq)
Demand for investment goods PqIq=αIqS
Price of imports in local currency PMq=(1+tmq)PWMqER
Price of exports in local currency PEq=PWEqER
Armington function Xq=aAq[ γAqMq(σAq1)σAq+(1γAq)XDDq(σAq1)σAq ]σAq(σAq1)
Armington FOC for imports Mq=XqaAq(γAqPMq)σAq[ γAqσAqPMq(1σAq)+(1γAq)σAqPDDq(1σAq) ]σAq(1σAq)
CET function XDq=aTq[ γTqEq(σTq1)σTq+(1γTq)XDDq(σTq1)σTq ]σTq(σTq1)
CET FOC for exports Eq=XDqaTq(γTqPEq)σTq[ γTqσTqPEq(1σTq)+(1γTq)σTqPDDq(1σTq) ]σTq(1σTq)
Market clearing condition for labour q=12Lq+LG=LS
Market clearing condition for capital q=12Kq+KG=KS
Market clearing condition for commodity q XDq+Mq(1+tmq)=s=12ioqsXDq+CGq+Cq+Iq+Eq
Income definition Y=PKKS+PLLS+TFPC
Disposable income minus savings CBUD=(1ty)YS
Zero profit condition in production function PDqXDq=PKKq+PLLq+s=12iosqXDqPDs
Zero profit condition in Armington function PqXq=PMqMq+PDDqXDDq
Zero profit condition in CET function PDqXDq=PEqEq+PDDqXDDq
Demand of commodity q by government PqCGq=αCGq(TAXREVTFPC)
Demand of capital by government PKKG=αKG(TAXREVTFPC)
Demand of labour by government PLLG=αLG(TAXREVTFPC)
Tax revenues TAXREV=tyY+q=12(tmqPWMqER)
Table 9
Simulation results: percentage changes (CGE model).
Integrated Approach Top-Down Approach TD/BU Approach (C&LS) TD/BU Approach (LS)
Government Surplus 0.00 0.00 0.00 0.00
Wage Rate −14.87 −14.67 −14.42 −14.64
Capital Return 19.70 19.30 17.91 19.13
Consumer Price Index 0.00 0.00 0.00 0.00
Exchange Rate 53.83 53.76 53.83 53.70
Labour Supply −1.00 −1.18 −1.32 −1.32
Government Use of Labour 4.82 4.23 3.72 4.06
Government Use of Capital −25.45 −25.45 −24.72 −25.43
Income* −9.50 −9.39 −9.50 −9.48
Disposable Income* −9.50 −9.39 −9.50 −9.48
Consumption Expenditure* −9.50 −9.39 −7.90 −9.48
Marginal Propensity to Save 0.00 0.00 −16.22 0.00
Savings* −9.28 −9.39 −24.18 −9.48
Tax Revenues −9.28 −9.48 −9.63 −9.58
  1. *

    For the integrated model, these changes are computed as average percentage changes across households.

Table 10
Simulation results: percentage changes (CGE model).
Macro variables Integrated Approach Top-Down Approach TD/BU Approach (C&LS) TD/BU Approach (LS)
Sector 1 Sector 2 Sector 1 Sector 2 Sector 1 Sector 2 Sector 1 Sector 2
Commodity Prices −0.99 0.30 −1.23 0.38 −1.70 0.52 −1.27 0.39
Domestic Sales −8.69 −12.52 −8.81 −12.54 −10.21 −12.05 −8.88 −12.64
Domestic Production 27.81 −14.20 27.91 −14.31 26.77 −13.86 27.84 −14.43
Labour Demand 43.52 −13.22 43.05 −13.36 41.08 −12.94 42.88 −13.48
Capital Demand 13.07 −26.82 13.14 −26.72 12.72 −25.84 13.15 −26.76
Consumption* −8.60 −9.78 −8.26 −9.73 −6.58 −8.30 −8.32 −9.84
Investment −7.65 −8.84 −8.26 −9.73 −22.87 −24.57 −8.32 −9.84
Imports −32.92 −47.63 −33.11 −47.57 −34.37 −47.21 −33.16 −47.60
Exports 207.36 −78.38 209.23 −78.53 209.10 −78.48 209.11 −78.59
  1. *

    For the integrated model, these changes are computed as average percentage changes across households.

Table 11
Simulation results: Inequality indices on disposable per capita real income (MS model).
Benchmark Values Integrated Approach* Top-Down Approach* TD/BU Approach (C & LS)* TD/BU Approach (LS)*
Gini Index 31.85 3.02% 1.68% 1.52% 1.66%
Atkinson’s Index, ε = 0.5 8.46 4.94% 3.01% 2.72% 2.97%
Coefficient of Variation 65.86 3.78% 2.84% 2.64% 2.81%
Generalized Entropy Measures:
I(c), c = 2 21.69 7.69% 5.75% 5.35% 5.70%
Mean Logarithmic Deviation, I(0) 17.72 3.99% 2.10% 1.83% 2.07%
Theil Coefficient, I(1) 17.82 5.89% 3.89% 3.58% 3.85%
  1. *

    Percentage deviations from benchmark values.

Table 12
Simulation results: Poverty indices on disposable per capita real income (MS model).
Benchmark Values Integrated Approach* Top-Down Approach* TD/BU Approach (C & LS)* TD/BU Approach (LS)*
General Poverty Line
Headcount Index, P0 40.98 56.00% 8.00% 8.00% 8.00%
Poverty Gap Index, P1 9.84 119.46% 27.25% 27.01% 27.21%
Poverty Severity Index, P2 0.00 143.04% 28.95% 28.51% 28.88%
Extreme Poverty Line
Headcount Index, P0 4.92 166.67% 33.33% 33.33% 33.33%
Poverty Gap Index, P1 1.00 71.09% 4.77% 4.64% 4.75%
Poverty Severity Index, P2 0.00 45.33% −0.03% 0.03% −0.03%
  1. *

    Percentage deviations from benchmark values.

Table 13
SAM of the economy made consistent with the Household Survey.
C1 C2 S1 S2 K L H G SI RoW Total
C1 57.8 15.6 95.4 62.6 28.1 23.6 283.0
C2 17.1 23.5 313.2 48.8 13.6 76.6 492.8
S1 283.3 283.0
S2 492.5 492.8
K 73.4 23.2 13.2 109.8
L 81.7 353.8 117.5 552.6
H 109.8 552.6 38.7 701.2
G 12.3 17.7 250.8 280.8
SI 41.7 41.7
RoW 40.8 59.4 100.2
Total 283.0 492.8 283.0 492.8 109.8 552.6 701.2 280.8 41.7 100.2
  1. Notes: Cq: consumption of good q; Sq: production sector q; K: capital account; L: labour account; H: representative household account; G: public sector; SI: savings-investments account, RoW: Rest of the World account.

Table 14
Simulation results with consistent data: Percentage changes (CGE model).
TD/BU Approach (C & LS) TD/BU Approach (LS)
Government Surplus 0.00 0.00
Wage Rate −14.63 −14.81
Capital Return 18.36 19.37
Consumer Price Index (num.) 0.00 0.00
Exchange Rate 53.90 53.80
Labour Supply −1.18 −1.18
Government Use of Labour 4.13 4.42
Government Use of Capital −24.89 −25.48
Income −9.45 −9.43
Disposable Income −9.45 −9.43
Consumption Expenditure −8.14 −9.43
Marginal Propensity to Save −14.13 0.00
Savings −22.24 −9.43
Tax Revenues −9.57 −9.52
Table 15
Simulation results with consistent data: Percentage changes (CGE model).
TD/BU Approach (C & LS) TD/BU Approach (LS)
Sec 1 Sec 2 Sec 1 Sec 2
Commodity Prices −1.44 0.44 −1.07 0.33
Domestic Sales −9.86 −12.06 −8.89 −12.55
Domestic Production 26.77 −13.80 27.65 −14.27
Labour Demand 41.65 −12.85 43.17 −13.30
Capital Demand 12.70 −25.99 13.05 −26.76
Consumption −7.13 −8.45 −8.45 −9.73
Investment −21.11 −22.58 −8.45 −9.73
Imports −34.12 −47.30 −33.10 −47.63
Exports 207.50 −78.34 207.46 −78.43
Table 16
TD/BU-C&LS approach with consistent data: RH shares from CGE model used in the MS model (percentage changes, CGE model).
only ty only ΔLS only ηi & mps ΔLS, ty, mps & ηi
Marginal propensity to save Savings 2.92 −14.82 −14.47 0.12
Savings −6.78 −22.87 −22.55 −9.33
Table 17
Simulation results TD/BU approach: percentage changes (CGE model).
ΔLS & ty (inconsistent data) ΔLS, ty, mps & ηi (inconsistent data) ΔLS, ty, mps & ηi (consistent data)
Government Surplus 0.00 0.00 0.00
Wage Rate −14.70 −14. 62 −14.84
Capital Return 19.43 18.95 19.46
Consumer Price Index (num.) 0.00 0.00 0.00
Exchange Rate 53.90 53.95 54.02
Labour Supply −1.18 −1.18 −1.18
Government Use of Labour 2.26 2.13 1.62
Government Use of Capital −26.96 −26.69 −27.55
Income −9.39 −9.40 −9.44
Disposable Income −8.47 −8.48 −8.12
Consumption Expenditure −8.47 −7.93 −8.14
Marginal Propensity to Save 0.00 −5.53 0.25
Savings −8.47 −13.54 −7.89
Tax Revenues −10.95 −10.97 −11.60
Table 18
Simulation results TD/BU approach: percentage changes (CGE model).
ΔLS & ty (inconsistent data) ΔLS, ty, mps & ηi (inconsistent data) ΔLS, ty, mps & ηi (consistent data)
Sec 1 Sec 2 Sec 1 Sec 2 Sec 1 Sec 2
Commodity Prices −1.21 0.37 −1.38 0.42 −1.09 0.33
Domestic Sales −8.75 −12.00 −9.27 −11.77 −8.92 −11.73
Domestic Production 28.13 −13.75 27.72 −13.53 27.87 −13.42
Labour Demand 43.37 −12.79 42.66 −12.58 43.46 −12.44
Capital Demand 13.28 −26.30 13.11 −25.93 13.20 −26.07
Consumption −7.35 −8.81 −6.90 −8.24 −7.45 −8.35
Investment −7.35 −8.81 −12.33 −13.91 −6.88 −8.19
Imports −33.09 −47.31 −33.57 −47.16 −33.20 −47.23
Exports 210.17 −78.31 210.17 −78.27 208.79 −78.11
Table 19
Simulation results TD/BU approach: percentage changes (MS model).
ΔLS & ty (inconsistent data) ΔLS, ty, mps & ηi (inconsistent data) TD Approach (inconsistent data)
Sec 1 Sec 2 Sec 1 Sec 2 Sec 1 Sec 2
Consumption −7.23 −8.28 −7.45 −8.35 −7.21 −8.28
Savings −7.78 −7.88 −7.78
Table 20
Inequality indices on disposable per capita real income (MS model).
Benchmark Values ΔLS & ty (inconsistent data)* ΔLS, ty, mps & ηi (consistent data)*
Gini Index 31.85 1.70% 1.66%
Atkinson’s Index, ε = 0.5 8.46 3.04% 2.97%
Coefficient of Variation 65.86 2.86% 2.81%
Generalized Entropy Measures:
I(c), c = 2 21.69 5.80% 5.70%
Mean Logarithmic Deviation, I(0) 17.72 2.13% 2.07%
Theil Coefficient, I(1) 17.82 3.93% 3.85%
  1. *

    Percentage deviations from benchmark values

Table 21
Poverty indices on disposable per capita real income (MS model).
Benchmark Values ΔLS & ty (inconsistent data)* ΔLS, ty, mps & ηi (consistent data)*
General Poverty Line
Headcount Index, P0 40.98 8.00% 8.00%
Poverty Gap Index, P1 9.84 27.30% 27.21%
Poverty Severity Index, P2 0.00 29.01% 28.88%
Extreme Poverty Line
Headcount Index, P0 4.92 33.33% 33.33%
Poverty Gap Index, P1 1.00 4.79% 4.75%
Poverty Severity Index, P2 0.00 −0.03% −0.03%
  1. *

    Percentage deviations from benchmark values

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