This study examines the contribution of professional codes to the prod
uction of trust in accounting services. Professional codes and their e
nforcement are only one possible input which society has at its dispos
al for the production of this trust. Other inputs include civil and cr
iminal codes. If society is modeled as a multi-input firm, then it wil
l tend to use less of any input as that input grows less productive or
more costly. To identify factors which might impact society's future
use of accounting self-regulation as a trust-producing input, the prod
uctivities and costs of enforcing professional codes in accounting are
modeled. The effectiveness of professional enforcement is seen to hav
e its origin in the losses members face if they leave the profession.
These exit costs are analyzed in detail. Other factors affecting profe
ssional enforcement are also evaluated. Trends in these factors are su
ggested, but empirical verification of them is not attempted. Finally,
the paper offers a reduced mathematical model which formally derives
some of the important results described earlier in the paper. Among th
ese are the ideas that monopoly rents and specificity of skills are im
portant in creating the conditions which make professional enforcement
possible. As these deteriorate, society's reliance on professional en
forcement will decline, and its dependence on courts will rise.