We propose a theory of firm dynamics in which workers have ideas for new projects that can be sold in a market to existing firms or implemented in new firms: spin-offs. Workers have private information about the quality of their ideas. Because of an adverse selection problem, workers can sell...

Novel early stage ideas face uncertainty on the expertise needed to elaborate them, which creates a need to circulate them widely to find a match. Yet as information is not excludable, shared ideas may be stolen, reducing incentives to innovate. Still, in idea-rich environments inventors may...