Social Interactions and Networks
Enough has been said to suggest that market-based theories give an inadequate
account of the effects of racial discrimination on economic magnitudes and the
effects of the economic system on racial discrimination. It is increasingly recognized
that many social interactions with economic implications are not mediated through
a depersonalized market, but rather through the cumulative effect of individual
choices. An early example is Schelling's (1971) analysis of residential segregation.
He started with preferences towards the races of neighbors but pointed out that
even mild discriminatory attitudes, if widespread, might lead to a very segregated
equilibrium. Implicitly, he assumed that it was not possible to have discriminatory
prices in a given location, for example, lower rents for whites in predominantly
black neighborhoods.
The hypothesis that prices do not reflect every kind of social interaction, even
those of economic importance, is used in many contexts. Every now and then,
economists studying the labor market have found it important to postulate some
kind of rigidity of relative wages. For example, Dunlop's (1957) study showed that
the wages of the same occupation, truck drivers, varied with the general wage levels
of the different industries which employed them. Similarly, a frequently-maintained
hypothesis about unemployment is that there is some fair level of wages which must
be maintained (for example, Hahn and Solow, 1995, ch. 5).
I intend these points as an illustration of a more general principle-that beliefs
and preferences may themselves be the product of social interactions unmediated
by prices and markets. This concept has been the object of significant theoretical
research recently (for example, Blume, 1997; Durlauf, 1997a, b) and empirical
application to the frequency of criminal activity (Glaeser, Sacerdote, and Scheinkman,
1996).
Another variation of the theme that social linkages alter resource allocation
processes is found in the concept of social capital that was introduced by Loury
(1977), developed by Coleman (1990, ch. 12) and used empirically, among others,
by Putnam (1993) and Borjas (1992). These scholars have hypothesized that a dense
98 Journal of Economic Perspectives
network of social connections, even though developed for noneconomic purposes,
will enhance both political and economic efficiency. Admittedly, the concept of
social capital is very hard to pin down in an explicit model, but enough has been
done to show its importance.
I want to conclude by concentrating on one particular type of social structure
which has already shown its applicability to the labor market, the network of acquaintances
and friends. Sociologists and some economists who have worked in this
area have shown by careful empirical work that a very large fraction of the jobs are
filled by referrals by current employees. There are many such studies; for especially
careful and definitive ones, see Rees and Shultz (1970, ch. 13) and Granovetter
(1974). The network concept of labor allocation differs considerably from a market.
It is indeed very easy to say how social segregation can give rise to labor market
segregation through network referrals. Discrimination no longer has any cost to
the discriminator; indeed, it has social rewards. Profit maximization is overcome by
the values inherent in the maintenance of the network or other social interaction.
The methodological demands which are satisfied by a network approach have been
outlined by Granovetter (1988) and White (1995). More definite modeling of networks
in the labor market still needs to be done. Clearly, the anonymous market,
in which in effect every seller is connected with every buyer, is one extreme of a
network. Intuitively, it is clear that a sufficiently dense network will mimic a market
(Kranton and Minehart, 1997). But the empirical accounts of employment suggest
instead a network with relatively few links compared with all those possible.
The main point is that personal interactions occur throughout this process,
and therefore there is plenty of room for discriminatory beliefs and preferences to
play a role which would be much less likely in a market subject to competitive
pressures. The network model seems most appropriate for the labor market, and
perhaps less so for the housing, automobile, and credit markets. But in all of these,
each transaction is a social event. The transactors bring to it a whole set of social
attitudes which would be irrelevant in the market model.
Models of racial discrimination in which all racial attitudes are expressed
through the market will get at only part of the story. At each stage, direct social
transactions unmediated by a market play a role. Even the market manifestations
will be altered by these direct social influences.