Just recently I we wrote an addendum consent form for our PI's to use
in such as case.  To back up and explain, we had a faculty member utilize
his employees in "unpaid" research as part of their employment.  As a result,
we looked into this issue and found that it is coercise.  If you have a copy
of the OPRR Guidebook, check Section 6 (Special Classes of Subjects), page
52-55.  These pages explainl
 it all and bring up other topics for discussion.
I'll fax you our addendum consent and these pages if you don't have access
to them.

Rebecca Bacon
Eastern Virginia Medical School
xxxxxx@picard.evms.edu