Imperfect or asymmetric information
There are typically good reasons to believe that markets
fail to produce optimal outcomes because of lack of
information. If people do not have sufficiently accurate
information on the costs and benefits associated with
a particular course of action, they may invest less. For
example, parents investing in their child’s education may
not be fully aware of the wide-ranging, monetary and
non-monetary long-term benefits of education, in which
case they will invest less than they would, had they been
aware of those benefits.
Not only can information be imperfect but it can be also
distributed asymmetrically in the market. Typically sellers
know the characteristics of the good they are selling
much better than buyers, and might thus be tempted
to profit from this informational advantage by selling a
poor-quality good at a high price. Similarly, the person
commissioning a work or a service is less informed about
the details of the technology and the costs of production
compared to the one actually doing the work. The latter
might exploit the principal’s ignorance by performing a
low-quality service while pretending it is high quality. These
behaviours can eventually lead to the closure of some
markets. Credit and insurance markets are particularly
plagued by asymmetric information problems and even
in developed countries are largely imperfect (and in the
rural areas of developing countries they are virtually
absent) (box 2.3).
2.2.2 Externalities
So-called “internal” and “external” costs combined make
up the total or “social” costs associated with a disease or a
risk factor. External costs and benefits begin where internal
costs and benefits end and comprise all those costs and
benefits that are not borne or taken into account by the
decision-maker. Drawing the line between internal and
external consequences is of critical public policy relevance.
Internal costs are the “private” costs borne by the individual,
knowingly or not, and are generally irrelevant to an argument
for government intervention within the efficiency rationale.
The most obvious internal costs associated with a disease
are the individual’s morbidity and mortality costs, easily the
greatest share of disease costs if converted into monetary
values.