Most nations have responded to the COVID-19 pandemic by locking down parts of their economies to reduce infectious spread. The optimal timing of the beginning and end of the lockdown, together with its intensity, is determined by the tradeoff between economic losses and improved health outcomes....

Electric utilities can reduce sulfur dioxide emissions through a variety of strategies such as adding scrubbers, switching to low- sulfur coal, or shifting output between generating plants with different emissions. The cost of achieving a given emission target can be minimized using a market for...

Drug producing regions often supply several geographically distinct drug consumption markets. Disruptions of opium cultivation in Afghanistan and cocaine production in Colombia show that consumption reductions can be much smaller in some final markets than are reductions in cultivation. This...