Pollution emitted by US manufacturers is falling while output is rising. What accounts for this cleanup? Prior studies attribute the majority to “technique,” a mix of input substitution, process changes, and end-of-pipe controls. But that estimate is a residual left over after calculating...

Most evidence suggests that the 1,000 or so different International Environmental Agreements (IEAs) operating today are ineffectual, merely ratifying business-as-usual outcomes. But much of that empirical analysis faces two obstacles: (1) limited data from before the IEAs were enacted and thus...