Is there any research that shows how the design of a sales incentive
system and the use of short-term vs long-term rewards affects a
salesperson's behavior?  The specific example I'm trying to understand
- would a salesman spend 4 hours to refer a client to an outside
specialist in order to receive a one time payment of $100, or would he
choose to service that client himself (spending 10 hours/yr) to
receive $100 in the first year and an annual payment of $50 in each
addtional year that client stays with him?