Free rider problems/tragedy of the anticommons - research that isn't directly patent-able would result in a dearth of private investment because there isn't a comparative advantage in researching it

Tragedy of the Commons - Research into monitoring, maintaining, regulating, and improving resources shared by private companies

Positive externalities - Some research will not pencil out without including return on investment that cannot be captured by a company

Negative externalities - Companies won't invest in research to reduce injury to other parties (could fix with regulation also but depending on specifics this may be very difficult to enforce)

awesome, thank you. You've given me some holiday reading at the very least :)