dM

dB

Maximised net benefits

M*

*

M

D(M)B(M)

D(M)

B(M)

M

Figure 6.4 Total and marginal damage and benefit functions, and the efficient level of flow pollution emissions.

dM

dD

Marginal damage

Marginal

abatement cost

£

0 M

Quantity of pollution

emission per period

M̂M*MA

*

C2C1

C3

Figure 6.5 The economically efficient level of pollution minimises the sum of abatement and damage costs.

t*

MH

Figure 6.6 Setting targets according to an absolute health criterion.

Emissions, M

Marginal health damage

MC

tH*

MH*

Figure 6.7 A ‘modified efficiency’ based health standard.

Emissions, M

Marginal health damage

MC

S1

S2

R4

R3

R2

R1

Figure 6.8 A spatially differentiated air shed.

r

1dM

dB

M*

*

M

**

M**

Figure 6.9 Efficient steady-state emission level for an imperfectly persistent stock pollutant. Two cases: {r = 0 and > 0} and {r > 0 and > 0}.

dM

dB

dM

dD

M̂

A

Figure 6.10 Threshold effects and irreversibilities.

Figure 6.10a A threshold effect in the decay rate/pollution stock relationship .

A

Figure 6.10(b) An irreversibility combined with a threshold effect.

• •a b

x

f(x)

Figure 6.11 A strictly convex function

MS M

D

D

MD = dD/dM

MS

MD

M

Figure 6.12 A non-convex damage function arising from pollution reaching a saturation point.

Marginal benefit

Marginal

damage

£

0 M

Quantity of pollution

emission per period

M2M1

b

C

a

Figure 6.14 A non-convex damage function arising from pollutants harmful at low concentrations but beneficial at higher concentrations.

M3 M4