The environment as a policy problem‘non-rival’ and ‘non-excludable’. They are ‘non-rival’ because one individual’s
consumption does not limit the consumption of others: someone breathing
clean air (normally) does not stop another individual also enjoying clean air.
Public goods are ‘non-excludable’ in that, if one individual refrains from a
polluting activity (e.g. driving a car), others cannot be excluded from the
resulting benefits (cleaner air). By contrast, with private goods (a washing
machine or a handbag), rivals can be excluded by the law of property (Weale
1992 : 5).
The public nature of environmental problems has important consequences
forpolicymakers because efforts to protect the environment may encounter
significant collective-action problems. The benefits to be gained from using a
public good are often concentrated among a handful of producers while the
costs may be spread widely: for example, a power station releasing sulphur
dioxide that will eventually fall as acid rain far away, or a factory dumping
chemicals into a river that pollutes it for miles downstream. If a government
wishes to prevent this pollution, the cost of dealing with the problem may
fall largely on the polluter, which in these examples would be the electricity
generator orthefactory-owner. Consequently, a small number of spatially
concentrated polluters who may have to pay for clean-up measures have an
incentive to act collectively to protect their interests (perhaps by dissuading
thegovernment from taxing the pollution), whereas the individual citizens
who suffer from the pollution are generally ill-informed, geographically dis-
persed and insufficiently motivated to mobilise as a group in defence of
their interests (Olson 1965 ).
Furthermore, if individuals cannot be excluded from the benefits that
others provide, then each has the incentive tofree-rideon the joint efforts
of others to solve the problem (ibid.). So, if a government exhorts citizens to
save water by refraining from ‘unnecessary’ activities such as washing cars
or watering lawns, or it seeks to prevent air pollution by asking people to
use their cars less, there will be a strong temptation for individuals to ignore
these instructions in the expectation that others will be more dutiful. Free-
riding will therefore result in a less than optimal provision of the collective
benefit, which in these examples would be a constant water supply or clean
air.
It is also useful to distinguish betweencommon-pool resources(Ostrom 1990 :
30) andcommon-sink resources(Weale 1992 :192–5). Common-pool resource
systems are sufficiently large for it to be costly, though not impossible, to
exclude potential beneficiaries from using them; they include fauna, forests
and fish stocks. People benefit from these stocks by depleting the common
pool, so the challenge for policymakers is to ensure that, say, the fishing
fleets of different nations do not catch more fish than is prudent for the
maintenance of the overall stocks. As common-pool resources can be indi-
vidually appropriated – elephants can be shot, trees chopped down, fish
caught – they are not pure public goods, although they share many
attributes.^3 However, common-sink resources, such as fresh air, are pure