This paper develops a resource-based--knowledge-based-theory of the fi
rm. Its thesis is that the organizational mode through which individua
ls cooperate affects the knowledge they apply to business activity. We
focus on the polar cases of organization within a firm as compared to
market contracting. There will be a difference in the knowledge that
is brought to bear, and hence in joint productivity, under the two opt
ions. Thus, as compared to opportunism-based, transaction-cost theory,
we advance a separate (yet complementary) answer to the question: why
do firms exist? Our aim is to develop an empirically relevant and com
plementary theory of why firms are formed: a theory based on irreducib
le knowledge differences between individuals rather than the threat of
purposeful cheating or withholding of information. We assume limited
cognitive abilities on the part of individuals (bounded rationality),
and assume that opportunistic behavior will not occur. The latter allo
ws us to determine whether resource-based theory has independent force
, as compared to the opportunism-based, transaction-cost approach. The
paper predicts choice of organizational mode, identifying whether fir
m organization or market contracting will result in the more valuable
knowledge being applied to business activity. The resource-based predi
ctions of organizational mode are compared and contrasted with corresp
onding opportunism-based, transaction-cost ones. A principal point is
that knowledge-based considerations can outweigh opportunism-related o
nes. The paper also establishes the relation of a theory of the firm t
o a theory of performance differences between competing firms.