What is the best way to allocate shares in a startup where half the potential founders are professors at an academic institution?
In this situation the professors have developed the technology over a number of years with money from grants combined with the use of university facilities. Naturally, the university will take an equity stake in the company when it licenses the technology to the company. It is in the interest of the company to keep the professors involved as our product is approximately 2/3 complete and will require input from the professors after the company is founded. As expected the professors do not want to leave their secure jobs to take part in the startup. Alongside the professors, there will be an additional 2 founders of the company. What is the most equitable way to allocate shares to reward the professors for their years of hard work developing the technology and to keep their interest in participating with the company after it is founded? I have read Joel Spolsky's comment on share allocation, but think this situation is unique enough to warrant a more specific answer.
I understand that engaging the professors as paid consultants to the company is one way to keep them involved after formation, but is it really reasonable to put all the emphasis on the future when allocating company shares?
Thanks in advance.