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Social, Economic, and Ethical Concepts and Methods
3
Chapter 3
P
g
– P
n
. Alternatively, a tax of (P
g
– P
n
) per unit of pollution would raise
the firm’s cost to SMC and result in equilibrium quantity Q’.
The diagram in Figure 3.3 will be used below to show how the equiva-
lence of these instruments breaks down under more general circum-
stances, as well as gains and losses to various groups. In other words,
we use this diagram to discuss economic as well as distributional,
other environmental and cultural objectives, and institutional / political
feasibility.
3�7�1�1 Economic objectives
Economic efficiency� Consider an economy’s allocation of resources
(goods, services, inputs, and productive activities). An allocation is effi-
cient if it is not possible to reallocate resources so as to make at least
one person better off without making someone else worse off. This
is also known as the Pareto criterion for efficiency (discussed in Sec-
tion 3.6.1) (see e. g., Sterner, 2003; Harrington etal., 2004; Tietenberg,
2006). In Figure 3.3, any reduction in output from Q
0
improves effi-
ciency because it saves costs (height of SMC) that exceed the benefits
of that output (height of PMB).
24
This reduction can be achieved by a
tax levied on the externality (a carbon tax), or by tradeable emission
permits. Further reductions in output generate further net gains, by the
extent to which SMC exceeds SMB, until output is reduced to Q’ (where
SMC=SMB). Hence, the gain in economic efficiency is area C. Perfect
efficiency is difficult to achieve, for practical reasons, but initial steps
from Q
0
achieve a larger gain (SMC>SMB) than the last step to Q’
(because SMC≈SMB near the left point of triangle C).
An aspect of economic efficiency over time is the extent to which a
carbon policy encourages the right amount of investment in research,
innovation, and technological change, in order to reduce GHG emis-
sions more cheaply (Jung etal., 1996; Mundaca and Neij, 2009). See
Section 3.11.
Cost-effectiveness� Pollution per unit of output in Figure 3.3 is fixed,
but actual technologies provide different ways of reducing pollution
per unit of output. A policy is cost-effective if it reduces pollution
(given a climate target) at lowest cost. An important condition of cost-
effectiveness is that marginal compliance costs should be equal among
parties (ignoring other distortions such as regulations) (Babiker etal.,
2004).
Transaction costs� In addition to the price paid or received, market
actors face other costs in initiating and completing transactions. These
costs alter the performance and relative effectiveness of different poli-
cies and need to be considered in their design, implementation, and
assessment (Mundaca etal., 2013; see also Matthews, 1986, p.906).
24
Other approaches are discussed in Section 3.6.
3�7�1�2 Distributional objectives
Six distributional effects� A policy may generate gains to some and
losses to others. The fairness or overall welfare consequences of these
distributional effects is important to many people and can be evalu-
ated using a SWF, as discussed in Section 3.4.6. These effects fall into
six categories (Fullerton, 2011), and are illustrated in Box 3.6 below. In
Figure 3.3, any policy instrument might reduce the quantity of pollut-
ing output, such as from Q
0
to Q’, which reduces emissions, raises the
equilibrium price paid by consumers (from P
0
to P
g
), and reduces the
price received by firms (from P
0
to P
n
). The six effects are illustrated in
Box 3.6. The framework can be applied to any environmental problem
and any policy to correct it.
With reference to Box 3.6, the first effect of a carbon policy on con-
sumers is generally regressive (though most analyses are for developed
countries), because the higher price of electricity imposes a heavier
burden on lower income groups who spend more of their income on
electricity (Metcalf, 1999; Grainger and Kolstad, 2010). However, fuel
taxes tend to be progressive in developing countries (Sterner, 2011).
The sign of the second effect, on factors of production, is generally
ambiguous. The third effect is regressive if permits are given to firms,
because then profits accrue to shareholders who tend to be in high-
income brackets (Parry, 2004). But if government captures the scar-
city rents by selling permits or through a carbon tax, the funds can be
used to offset burdens on low-income consumers and make the overall
effect progressive instead of regressive. Other effects are quite difficult
to measure.
Much of the literature on ‘environmental justice’ discusses the poten-
tial effects of a pollution policy on neighbourhoods with residents from
different income or ethnic groups (Sieg etal., 2004). Climate policies
affect both GHG emissions and other local pollutants such as SO
2
or
NO
X
, whose concentrations vary widely. Furthermore, the cost of miti-
gation may not be shared equally among all income or ethnic groups.
And even ‘global’ climate change can have different temperature
impacts on different areas, or other differential effects (e. g., on coastal
areas via rise in sea level).
The distributional impacts of policies include aspects such as fairness /
equity (Gupta etal., 2007). A perceived unfair distribution of costs and
benefits could prove politically challenging (see below), since efficiency
may be gained at the expense of equity objectives.
3�7�1�3 Environmental objectives
Environmental effectiveness� A policy is environmentally effective
if it achieves its expected environmental target (e. g., GHG emission
reduction). The simple policies mentioned above might be equally
effective in reducing pollution (from Q
0
to Q’ in Figure 3.3), but actual
policies differ in terms of ambition levels, enforcement and compli-
ance.
Box 3�6 | Six distributional effects of climate policy, illustrated for a permit obligation or emissions
tax on coal-fired electricity, under the assumption of perfectly competitive electricity markets
First, the policy raises the cost of generating electricity and if cost
increases are passed through to consumers, for example through
competitive markets or changes in regulated prices, the consum-
er’s price increases (from P
0
to P
g
), so it reduces consumer surplus.
In Figure 3.3, the loss to consumers is the sum of areas A + D.
Losses are greater for those who spend more on electricity.
Second, the policy reduces the net price received by the firm (from
P
0
to P
n
), so it reduces producer surplus by the sum of areas B + E.
The effect is reduced payments to factors of production, such as
labour and capital. Losses are greater for those who receive more
income from the displaced factor.
Third, pollution and output are restricted, so the policy generates
‘scarcity rents’ such as the value of a restricted number of permits
(areas A + B). If the permits are given to firms, these rents accrue
to shareholders. The government could partly or fully capture the
rents by selling the permits or by a tax per unit of emissions (Ful-
lerton and Metcalf, 2001).
Fourth, because the policy restricts GHG emissions, it confers ben-
efits on those who would otherwise suffer from climate change.
The value of those benefits is areas C + D + E.
Fifth, the electricity sector uses less labour, capital and other
resources. It no longer pays them (areas E + F). With perfect
mobility, these factors are immediately redeployed elsewhere,
with no loss. In practice however, social costs may be substan-
tial, including transaction costs of shifting to other industries or
regions, transitional or permanent unemployment, and social and
psychological displacement.
Sixth, any gain or loss described above can be capitalized into
asset prices, with substantial immediate effects for current own-
ers. For example, the value of a corporation that owns coal-fired
generation assets may fall, in line with the expected present value
of the policy change, while the value of corporations that own
low-emissions generation technologies may rise.
The connection between these distributional effects and
‘economic efficiency’ is revealed by adding up all the gains
and losses just described: the consumer surplus loss is A + D;
producer surplus loss is B + E; the gain in scarcity rents is A + B;
and the environmental gain is C + D + E, assuming the gainers
and losers receive equal weights. The net sum of the gains and
losses is area C, described above as the net gain in economic
efficiency.
In many cases, a distributional implication of imposing effi-
cient externality pricing (e. g., area A + B) is much larger than
the efficiency gains (area C). This illustrates the importance of
distributional considerations in discussions on emissions-reducing
policies, and it indicates why distributional considerations often
loom large in debates about climate policy.