We re-examine the efficiency of observable and unobservable crime protection decisions with new results and insights. Observable protection is unambiguously associated with a negative externality. At the individual level, it reduces the crime effort, but its unit payoff remains unchanged....

We analyse the production of electricity from n power stations in a dynamic model. Each power station's production of electricity is constrained by the quantity of water available to it (supply constraint) as well as limitations on reservoir capacity (storage constraint). We show that hydro...