This paper explores the trade-off between economic growth and environmental quality along two paradigms of endogenous growth theory: variety expansion (HIP) and quality improvements (VIP). We compare the policies that match the decentralised economies' paths with the optimal "strong sustainable"...

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...