Title: RAINS and Chapter 14
1RAINS and Chapter 14
2The Rains Model
- An example of applied environmental economics.
- Illustrates how economic theory is translated
into a real world model. - The lack of data makes compromises necessary.
- This implies a few warts.
3What is captured by the RAINS model?
- Several versions of the model, some with sulphur,
NOx, ammonia etc. - Here we focus on the sulphur model.
4Components of the Rains model
- 38 regions (For the most part countries). These
are the sources of pollution, ei. - 700 grid squares covering Europe, each 150 km
150 km. These are receptors of pollution, dj. - A meteorolocial model, a matrix where the
coefficent aij is the fraction of pollution from
i that ends up in j. - dj Siaij ei bj
- bj is exogenous depositions from sources not
covered in the model. Mainly United States
5More components of the Rains model
- Ecological consequences A function that maps
depositions into ecological consequences
fraction of ecosystems in a grid square that is
severly damaged. - These functions are called critical loads. The 5
critical load implies that 5 of ecosystems will
be destroyed or damaged. - Stepwise function (Draw figure on Board)
6The cost module
- For each source there is a purification cost
curve ci(ei). - Purification is the cost of reducing emissions
keeping output constant - Marginal cost curves in steps.
- Represented by ci ?iei Bi
7The model
- Minimise ?ci j1,2 , 38
- subject to ci ?iei Bi
- dj Siaij ei bj Di i 1,2,,700
- Di are usually n critical loads. That is we
allow 5 of the ecosystems in each grid to be
destroyed or severly damaged
8Feasibility
- Turns out 5 critical loads are not feasible.
(Cant be done) - Question is How to modify the model? Let us try
Gap Closure for the non-feasible constraints. - dj s(dj(historical) Dj) Dj.
- Here s is the percentage of closure
- Alternative Area exceedance closure
9Now Questions
- What compromises have been made?
- Exogenous output
- No valuation of damages. Arbitrary protection at
5 of ecosystems. - Gap Closure not even related to ecosystem
protection - So, is this a good model?
10Economy-Wide effects
- Into macro-economics and the effect of
environemental regulation on total productivity. - Issue 1. How does environmental protection
affect productivity. - Issue 2. How does environmental protection
affect our measures of productivity
11Productivity growth
- Production grows for three reasons
- Increased use of inputs (such as labor and
capital) - Increased efficiency
- Technological progress
- Problem right here. Production must be measured
properly, i.e. include environmental services.
However, all three may lead to less production of
environmental services.
12Total Factor Productivity Growth
- Consider the macro production function
YAf(L,K). - Here A is a technology variable assumed to
capture the effect of progress. (Einsteins theory
of relativity, The Slutsky Equation and the
invention of Tofu.)
13Some manipulations to decompose productivity
growth
- Differentiate to get
- ?Y ?Af(L,K) AFL?L AFK?K
- Divide by Y to get
- ?Y/Y
- ?A/A (LAFL/AY)(?L/L) (KAFK/AY)(?K/L)
- Use that pL pYAFLand pK pYAFK. and zero
profits in macro equilibrium to get -
14Finally
- Á/A Ý/Y sLL/L sKK/K
- Here sL pLL/(pLL PKK) and
- sK pKK/(pLL PKK)
- sK and sL are cost shares.
- Technological growth Á/A is the increase in
production not attributed to increased input use.
15The effect on prouctivity when we look at a bad
measure
- Productivity growth is often reported only as
Labour productivity growth. - What is the effect of environmental regulations
that raises the price of capital?
16Green National Accounting
- Why national accounting?
- Indispensable tool for planning purposes.
Macroeconomic policy without national accounting
does not make much sense. - Important metric for people with a size fetish.
My GDP is bigger than your GDP. - For both purposes it is important to get things
right.
17Example - China
- Example - China
- GDP per capita in 2004 US 5600
- US GDP per capita in 2004 US40100
- So USA is more than 7 times as rich as
- China
- China GDP per capita grew at 9.1 in 2004
- USA grew at 4.4
- If this continues
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19But something is a amiss
- Each year 400000 Chinese die from airpollution
- 70 of Chinas freshwater is polluted to the
point of being undrinkable - These things are not measured
20What can go wrong with national accounting
- Some things are not measured correctly or at all
- Goods not produced for sale in a market e.g.
raising kids, house cleaning, pollution induced
health problems. - Goods that are produced by government e.g. the
value of education - Prices do not reflect social cost
- Some things are categorized wrong.
- Extraction of natural resources such as fish and
oil represents (possibly) depletion of wealth
rather than production of income.
21National Accounting
- Y C G I A B.
- GDP equals Consumption Real Investment
Financial Investment through trade surplus. All
measured at market prices. - Here we only consider a closed economy without a
government.
22Deriving GDP measure from a Optimally Managed
Economy
- Consider the following economy
- Utility W?tU(ct)ßt with Kt1 Kt F(Kt,Rt)
dKt ct and Et1 Et f(Et) Rt - Lagrangian for this problem is
- ? ?t(U(ct)ßt ?(Kt1 Kt (F(Kt,Rt) dKt)
ct) µ (Et1 Et (f(Et) Rt)) - R is a natural resource
23Deriving GDP measure from a Optimally Managed
Economy
- Let us look at the first term in the Lagrangian
- (U(c0)ß0 ?(K01 K0 (F(K0,R0) dK0) ct)
µ (E0 1 E0 (f(E0 ) R0 )) - Does it look familiar?
- How about now?
- (U()c0ß0 ?(K01 K0 (F(K0,R0) dK0) ct)
µ (E0 1 E0 (f(E0 ) R0 ))
24The point
- If the market prices are equal to the shadow
prices and to marginal utility, GDP for period t
is equal to the corresponing term in the
Lagrangian! This can be shown formally but is a
bit tricky. - (U()c0ß0 ?(K01 K0 (F(K0,R0) dK0) ct)
µ (E0 1 E0 (f(E0 ) R0 )) -
- (pc0 pK(Capital investment) pE(Change in
resource stock))
25A wrongly calculated GDP
- (pc0 pK(Capital investment) pE(Resource
extraction)) - Two errors are made. Resource extraction counts
as positive when it should be negative (and vice
versa) - Note In a steady state economy this does not
matter.
26The relationship between wealth and GDP
- It can be proven that if NNP is measured
correctly then - Wealth NNP/Discount rate
- An increase in NNP implies higher utility
27Issues not touched upon
- Adjusting GDP for risk?
- Catastrophic risk. The easy way is NNP
- Pr(catastrophe in a year)Cost of catastrophe
- Risk distributed across population. Very
- contested topic
- Income distribution?
28Income distribution
- Although China is growing rapidly, a largepart of
the population is left behind. - Imposes political risk on future NNP development.
- Is a dollar to Farmer Poor Joe the same as a
dollar toBill Gates? - Is distributionally skewed NNP growth
sustainable?
29Income distribution - USA
- From 1985 to 2003, the richest 1 saw an
increase in income equal to 60 (adjusted for
inflation) - From 1985 to 2003, the richest 1 saw an increase
in income equal to 2 (adjusted for inflation) - Based on tax returns. The truth is even worse.
- Recipe for revolution