We observe that residual claimancy can be a source of rent in a princi
pal-agent relationship. We show that the choice between input or outpu
t monitoring will be chiefly determined by the identity of the residua
l claimant of the principal-agent relationship. The principal will fin
d input monitoring more efficient if the principal is the residual cla
imant, and he will find output monitoring more efficient if the agent
is the residual claimant. If residual claimancy is a choice, the princ
ipal will be the residual claimant under input monitoring. Under outpu
t monitoring, residual claimancy is not an issue. If both residual cla
imancy and the monitoring instrument can be chosen, the principal will
choose to monitor input and to be the residual claimant. Journal of E
conomic Literature Classification Numbers: D23, D82, L22. (C) 1995 Aca
demic Press, Inc.