We revisit optimal investment in energy-efficiency, presenting a decision framework built around the agent's wealth and wealth dynamic. An investment rule in the form of a trigger is derived such that the agent invests the first time the energy-carrier price crosses this threshold from below....

The ecological literature suggests that biodiversity reduces the variance of ecosystem services. Thus, conservative biodiversity management has an insurance value to risk-averse users of ecosystem services. We analyze a conceptual ecological-economic model in which such management measures...