4. "We have forgotten how to be good guests, how to walk lightly on the earth
as its other creatures do."
Barbara Ward, Only One Earth, 1972.
Rising CO2
Air pollution is most dangerous threats to our health and environment. It has
been a problem through history.
A Roman philosopher, Seneca, complained about air pollution in Rome in
61 CE, he wrote:
“As soon as I had escaped the heavy air of Rome and the stench
of its smoky chimneys, which when stirred poured forth
whatever pestilent vapours and soot they held enclosed, I felt a
change in my disposition.”
“The use of coal was prohibited in London in 1273, and at least one person
was put to death for this offense sometime around 1300. Why did it take
economists so long to recognize and analyze the problem?”
Anthony C. Fisher (1981, page 164)
6. The Top GHG Emitters
• It goes without saying that, just a few countries are responsible for
80% of the world’s GHG emissions. The top emitting countries are
(2011):
US constitute less than 5 % of global population but use about 24 % of
world’s energy. US resident use energy much greater than Chinese and
Indian. They emit 6 times more GHG than the Chinese and 18 times
more than the typical Indian.
7. Most Vulnerable Countries @ risk from Climate Change
1. Bangladesh
2. India
3. Madagascar
4. Nepal
5. Mozambique
6. Philippines
7. Haiti
8. Afghanistan
9. Zimbabwe
10. Myanmar
8. Carbon Pricing Instrument
• Protecting natural environment and human life through
reducing greenhouse gases especially carbon dioxide is
possible by carbon pricing instrument. One possible
instrument to curb of greenhouse gas emissions especially
carbon dioxide is the taxation of CO2 emissions
• It is clear that pricing carbon will significantly impact on
industries and end users in form of higher marginal cost and
commodity price respectively.
9. Environmental taxes by European
Commission classification
Energy
Excise duty on mineral oils
In-bond surcharge on mineral oils
In-bond surcharge on liquefied petroleum gases
Excise duty on liquefied petroleum gases
Excise duty on methane
Local surcharge on electricity duty
Excise duty on electricity
Tax on coal consumption
Transport
Motor vehicle duty paid by households
Motor vehicle duty paid by enterprises
Public motor vehicle register tax
Provincial tax on motor vehicles’insurance
Pollution
SO2 and NOx pollution tax
Contribution on sales of phytosanitary products and pesticides
Regional special tax on landfill dumping
Provincial tax for environmental protection
Regional tax on aircraft noise
11. Country CO2 Tax
Australia $24.151 per tCO2e (2013)
British Columbia CAD30 per tCO2e (2012)
Denmark USD31 per tCO2e (2014)
Finland EUR35 per tCO2e (2013)
France EUR7 per tCO2e (2014)
Iceland USD10 per tCO2e (2014)
Ireland EUR 20 per tCO2e (2013)
Japan USD2 per tCO2e (2014)
Mexico Mex $ 10 -50 per tCO2e 2014 Depending on fuel type
Norway USD 4-69 per tCO2e (2014) Depending on fuel type
South Africa R120/tCO2 (Proposed tax rate for 2016)
Sweden USD168 per tCO2e (2014)
Switzerland USD 68 per tCO2e 2014
United Kingdom USD15.75 per tCO2e (2014)
Carbon dioxide taxation in different countries
One ton of carbon (tc) equals 44/12 = 3.67 tons of carbon dioxide (t CO2)
12. Problem Synthesis
What are the impacts of carbon tax
on Italian macroeconomic variables?
What range of carbon tax is required
to achieve Italian Kyoto target?
13. Methods/Approaches
• A variety of models and methods have emerged to address
ecological footprint problems such as operational research
techniques, environmental input-output analysis,
computational general equilibrium (CGE), econometrics
techniques especially panel data analysis and so on .
• Acceptable approaches for this objective are the
environmental Input-Output (IO) models, and computable
general equilibrium (CGE) or applied general equilibrium
(AGE)
14. Computable General Equilibrium
Standard CGE is based on Walrasian economy and sometimes referred
to Lausanne school of economics or neoclassical economics.
A CGE model is a system of equations that describe an economy as a
whole and the interactions among its part.
This is opposed to “partial equilibrium” that only takes into account a
part of the system (e.g. labour market), which neglects potential
feedbacks.
CGE model is an algebraic representation of the abstract Arrow-
Debreu model. Because Arrow-Debreu’ model was so abstract,
general and tough also doesn’t include any numerical analysis, CGE
models are designed to convert their model from general form into
realistic of actual economy.
This is why they are called “Computable” because they should produce
numerical results that are applicable to particular situations.
15. Computable General Equilibrium
Models can be used for “what if” simulations thereby allowing one
to obtain numerical results for endogenous variables based on
assumptions about exogenous variables, functional forms, and
parameter values.
Most CGE models rest on neo-classical economic assumptions
Consumers are assumed to maximize their utility subject to a
budget constraint (demand-side).
Producers are assumed to maximize profit (or minimized cost),
given the prices of goods and factor of production costs (supply
side).
For each good and factor of production, equilibrium price is
calculated where that demand equals supply.
16. CGE cont.
The term general means that the model encompasses all economic
activity in an economy simultaneously.
Equilibrium: when supply and demand are in balance at some set of
prices and there are no pressures for the values of this variable to
change further. In CGE model, equilibrium occurs at that set of prices
at which all of agents like producers, consumers and so on
The excess demand ED can be defined as:
A Walrasian price vectors P* is such a price if:
ED (P*) =0
Walras suggests that equilibrium will be achieved through a process of tâtonnement "groping“.
(The proof of existence of Walrasian equilibrium is formalized by A.D by applying Brouwer-Kakutani
theorem)
17. CGE Advantages
are formulated based on solid microeconomics foundation
and incorporate many aspects of economic theory. Most of
them use neo-classical behavioral concepts (optimization &
choice) such as utility maximization and cost minimization to
characterize the workings of the economy.
CGE models also have the potential advantage of being highly
customizable. A model builder can construct any type of
functional form for example C.E.S, Leontief or Cobb-
Douglass and etc. then choose which variable should be
including in the model, in brief CGE models are flexible in
specifications.
CGE models are solved based on numerical methods not
analytically. There are many important non-linear equations
for which it is not possible to find an analytic solution.
18. CGE Disadvantages
CGE models are complex and require skill to maintain them.
They can be difficult to use, especially for non-expert readers.”
Without detailed programming knowledge, the CGE approach
is doomed to remain a “black box “for non-modelers”
(Rutherford et al).
CGE models are expensive, time consuming and sometime to
build a model takes some month.
When violations of assumptions lead to serious biases like
imperfect competition vs. monopoly markets
20. Top down vs. Bottom-up models
Bottom-up models emphasize on technological options, engineering information
and data by disaggregating the energy sector to simulate interaction energy
transformation technologies with demand for energy services.
Top- down models are very aggregated national-wide models and focus on
different market and economy wide feedbacks which allow better assessment of the
change in relative prices of the supply-demand interactions and incomes across the
markets. Top-down models often sacrificing the technological options which maybe
relevant to the energy policy.
21. Assumptions of Model
Markets are perfectly competitive
Zero profit conditions ( holds for all agents)
Market Clearance conditions ( holds for goods
and factors)
Producers maximize profits or minimize costs
Households maximize utility subject to income
Armington assumptions
Nested CES function for agents
22. Nested Production and Consumption Function
Intermediate goods
Output
CES
Value added
CES
CES
Imported
Intermediate
Domestic
Intermediate
Labour Capital Energy
Composite
Export
CET
Domestic
CES
DomesticImported
Consumption demand
Household’ consumption
Capital demand
Imported Domestic
CES
CES
23. Mixed Complementary Problem (MCP)
A complementarity problem is a problem where one of the
constraints is that the inner product of two elements of vector
space must equal zero. i.e x=(1,0) and y=(0,2)
: :
:
. : ( ) 0, 0, . ( ) 0
n n
n
T
Given f R R
Find z R
s t f z z z f z
24. Mathematical statements for Producers
{
, , ,
, , ,
1
1 1 1
, int,
1
1 1 1
, int,
1 0,
0, 1
klm s klm s klm s
klm s klm s klm s
s s KL s s s s g
s s KL s s s s g
unit revenue functionCES unit cost function
Z Ctax PVA PINT PO
Z Ctax PVA PINT PO
1 4 4 4 4 4 4 4 4 4 2 4 4 4 4 4 4 4 4 4 3
, , ,
1
1 1 1
, ,
kl s kl s kl s
s k s ke l s lPVA pf pf
int,
int,
1
11
, (1 )
s
s
s g s g s
g
PINT PD TX
int,,
, , int.(1 )
sklm s
s s
g s s s g s s
s g
PKLM PINT
D Ctax Z Q
PINT PD
, ,
, ,
. . .
. . .
klm kl
klm kl
s s
H s s kl s l s
S s s
s s
H GOV s s kl s k s
S s s
PO PKL
L Z Q W
PKL PL
PO PKL
K K Z Q W
PKL PK
25. Mathematical Statement for Consumers
{
1
11 1
1
11 1
exp
1 0,
0, 1
h con inv
h con inv
Hicksian welfare
CES unit enditure function priceindex
WELH Ctax CPI PKGD PW Utilityprice UtilityValue
WELH Ctax CPI PKGD PW
1 4 4 4 4 4 4 44 2 4 4 4 4 4 4 4 43
1
1
1
h
h
g g
g
CPI PD
1
1
1
,g kgd g
g
PKGD PD
,
,
(1 )
k
g con con g
g h
g
Income W Ctax PW CPI
CD
PW CPI PD
.. .g kgd inv
g
g
Income W PW PKGD
ID
PW PKGD PD
26. Mathematical statement for Government
,
.
. .
. .
. . .
gov h gov
h
gov K gov M S
g g g
g
S S S
s
s s g h g g
s
Y GOVEXP TRN
Y P K TAX TAX TRN CTAX
TAXM txm QM PM
TAXS txs Q PO
CTAX Ctax Z PO Ctax CD CPI
1
1
1
0
gov
gov
g g
g
WELGOV K PD GPI
,
.
gov
gov g
g gov
g
Y K GPI
CD
GPI PD
27. Mathematical statement for ROW
1 1
1 1 1
min . .g g g
g d g m
PD QD PMg QM
QTS QD QM
1
1 1 1
, ,
, ( )
.
d g m g g
g m g g
g
g global
PDg PM
QM QTS optimal M
PM
PM PFX PFM
1 1
1 1 1
max . .g g g
g d g m
PD QD PXg QX
QTS QD QX
1
1 1 1
, ,
, ( )
.
d g g x g g
x g g
g
g global
PX PD
QX QTS Optimal X
PX
PX PFX PXF
28. Mathematical Statement for Market Clearing
, , ,
Supply Demand
g g g s g g k g g g s
s k s
QIM QNO QFO QP QG QI QX QF
ÁÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÂ ÁÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÃÂ
, ,f h f s
h s
QOE QFE
Total import I+nventory Supply+ Activity Products= Household demand+Gove . Demand+Export+Interm. demand
29. Data and Software
Data obtained from international database like IEA, World
Bank especially WIOD and GTAP database, which includes
energy consumption as well as carbon dioxide emissions.
For analysing data, General Algebraic Modelling System
(GAMS) and its subsystem MPSGE deployed.
30. Social Accounting Matrix
Historically, the roots of Social Accounting Matrix (SAM)
and input output (I/O) table framework can be traced back to
French physician Francois Quesney with his famous Tableau
Economique (Economic Table) in 1758.
A SAM is the integration of input-output table and national
income accounts.
transform the data from the GTAP database (73× 73) into a
SAM (20×20).
SAM should be balanced for CGE model
31. Concordance between GTAP and WIOD
GTAP classification WIOD Author aggregation
paddy rice, wheat, cereal grains , vegetables, fruit, nuts, oil seeds
sugar cane, sugar beet, plant-based fibers, crops, cattle, sheep, horses
animal products, raw milk, wool, silk-worm cocoons.
C1
Agriculture and mining
forestry, fishing, coal, oil, gas, minerals. C2
meat: cattle, sheep, goats, horse, meat products , vegetable oils and fats, dairy products,
processed rice, sugar, food products , beverages and tobacco products, textiles, wearing
apparel, leather products, wood products, paper products, publishing, petroleum, coal
products, chemical, rubber, plastic prods, mineral products , ferrous metals, metals , metal
products, motor vehicles and parts, transport equipment , electronic equipment, machinery
and equipment , manufactures .
C3-C16 Manufacturing
electricity, gas manufacture, distribution, water, construction C17+C18 Utility and construction
trade, transport , sea transport, air transport, communication C19-C27
Transportation and
communication
financial services , insurance, business services, recreation and other services, public
administration/defense/health/educate, dwellings
C28-C35 Services
skilled labor, unskilled labor ------
Labor
capital, land, resources ------ Capital
33. Calibration
Calibration involves determining the numerical values
of unknown parameters of functions compatible in
some known equilibrium observed in SAM (Annabi,
N., et al. 2006, Hosoe, N., et al. 2010).
Calibration process is selecting parameter values in
such a way that once the model is replicated
benchmark data with these parameter values and
equilibrium is computed.
A 2004 Social accounting matrix of Italy has been
calibrated by MPSGE codes.
34. Some Parts of MPSGE output
---- VAR Z ACTIVITY LEVEL
LOWER LEVEL UPPER MARGINAL
AGR_A . 1.000 +INF .
MFG_A . 1.000 +INF .
Utilcon_A . 1.000 +INF .
TrNCM_A . 1.000 +INF .
Serv_A . 1.000 +INF .
35. Simulation Step
Computable general equilibrium (CGE) models a
help policy maker to assess the policy effects on the
economy among different agents within an economic
system.
The next step is exogenous variable which is carbon
tax parameter should be changed in simulation phase
under different scenarios to compute new equilibrium
(new policy equilibrium).
37. Model Simulation and Results analysis
Scenario 1 examines the impact of carbon tax without
revenue recycling (independent CO2 tax).
Scenario 2 simulates the combined effect of
imposition of carbon tax and the revenue generated
from CO2 tax recycled back to consumers to
compensate tax pressure on the economy.
42. Sensitivity analysis
In order to check the robustness of simulation
results Hosoe et al (2010) proposed 2 criteria:
1: The sign of the sectoral output changes
which should be unchanged in different cases.
2: The ordering of the output changes should be
sustained in all cases.
Result: 50% higher value and 50% lower value for
elasticity of substitution in nested production
function are applied , both criterion are satisfied
consequently our model is robust and reliable.
43. 5 $ per CO2 tone 10 $ per CO2 tone 20 $ per CO2 tone 50 $ per CO2 tone
α=0.5 α=1 α=1.5 α=0.5 α=1 α=1.5 α=0.5 α=1 α=1.5 α=0.5 α=1 α=1.5
Independenttax
Industry
GDP -0.01% -0.02% -0.03% -0.02% -0.03% -0.05% -0.03% -0.07% -0.10% -0.08% -0.20% -0.30%
WELH -0.10% -0.10% -0.10% -0.30% -0.30% -0.30% -0.60% -0.60% -0.60% -1.40% -1.40% -1.40%
WELGOV 0.50% 0.40% 0.40% 0.10% 0.90% 0.80% 0.20% 1.80% 1.60% 4.90% 4.40% 3.90%
CO2 Kt -888 -1,063 -1,239 -1,772 -2,120 -2,471 -3,526 -4,216 -4,909 -8,676 -10,355 -12,023
Energy -0.20% -0.30% -0.30% -0.40% -0.50% -0.60% -0.90% -1.10% -1.20% -2.20% -2.60% -3.00%
Industry
plus
Households
GDP -0.01% -0.02% -0.03% -0.01% -0.03% -0.05% -0.03% -0.06% -0.10% -0.07% -0.20% -0.50%
WELH -0.30% -0.30% -0.30% -0.60% -0.60% -0.60% -1.20% -1.20% -1.20% -3.00% -3.00% -5.80%
WELGOV 1.20% 1.10% 1.00% 2.30% 2.20% 2.10% 4.60% 4.30% 4.10% 11.20% 10.60% 19.50%
CO2 Kt -1,659 -1,826 -2,002 -3,308 -3,643 -3,990 -6,574 -7,237 -7,923 -16,125 -17,735 -37,408
Energy -0.40% -0.40% -0.50% -0.80% -0.90% -0.90% -1.50% -1.70% -1.90% -3.70% -4.20% -8.90%
44. Kyoto Target for Italy
Italy ratified the Kyoto protocol on June 2002. The Kyoto protocol commits Italy to reduce
its GHG emissions by about 6.5% with respect to 1990 level by 2008-2012.
According to UNFCCC Italian green house gas emissions excluding LULUCF were
519.1 MtCO2eq in base year. The Kyoto target is therefore set at 485.3 Mt CO2eq.
From the base year emissions Italy's assigned amount in accordance with Article 3,
paragraphs 7 and 8 is 2,426.5 MtCO2eq. The most important GHG in Italy was CO2
contributing averagely 84.1 per cent to total.
The Kyoto protocol has fixed the base year (1990) CO2 emissions for Italy to 436 million
tonne. Thus in order to meet Kyoto target Italian sectors should reduce CO2
emission around 1.2 million tonne in each followed year.
Our simulation results show by imposing tax between 5 and 10 dollar per tCO2 (18.35
and 36.7 dollar per tonne carbon) Italy could have met the Kyoto target by 2012.
However, as reported by European Environment Agency (2014) Italy’ GHG is not
fully on track towards its burden-sharing target and need to purchase additional
international credits before the end of the true-up period.
46. Limitation and Contribution of Study
Limitation are:
Only examined CO2 tax impacts on economy
Static model
Household aggregation
Contribution are:
Provide a literature review of previous research on the carbon tax
Extract Italy SAM from GTAP database and convert into
standard form
Prepare computer programs for numerical simulations
Conducting policy simulations with the models and interpret the
simulation results