Privacy, Publicity, and Choice
Working Paper No. 08-W09
Andrew F. Daughety and Jennifer F. Reinganum
ABSTRACT [article]
We develop and explore a new model
of the economics of privacy. Previous work has focused on
"privacy of type," wherein an agent privately knows an immutable
characteristic. We consider "privacy of action," wherein privacy
means that an agent's choice of action is unobservable to others.
To show how a policy of privacy can be socially optimal, we assume
that an agent derives utility from an action he takes, from the
aggregate of all agents' actions, and from other agents'
perceptions of the agent's type (that are based on his action).
If his action is observable, then he distorts it (relative to his
full-information optimal action) so as to enhance the perceptions
that others have of him. This contributes to aggregate welfare
through increasing the public good, but the disutility associated
with the distortion of agents' actions is also a social cost. If
his action is unobservable, then he can take his full-information
optimal action and still be "pooled" with other types. When the
disutility of distortion is high relative to the marginal utility
of the public good, a policy of privacy is optimal. We also
consider a policy of waivable privacy, and find that equilibria
exist in which some, but not all, types waive privacy. More
significantly, if policies of privacy or publicity are costlessly
enforceable, then a policy of waivable privacy is never socially
preferred. Finally, we consider a number of examples (some of
which involve a public bad and/or social disapproval):
open-source software development; charitable giving; recycling;
consumption of health services; DNA dragnets; student rankings;
constraints on information disclosure at trial; electricity and
water usage during periods of voluntary rationing; shaming of
speeders; and the use of earmarks by Congress.
Keywords and Phrases: Privacy, public goods, disclosure, signaling, esteem
JEL Classification Numbers: H41, K39, D82