The Porter Hypothesis argues that environmental regulations benefit firms by fostering innovation. We discuss four examples consistent with this idea, highlighting either the distribution of benefits or costs, or the presence of some additional distortion, other than pollution. Examples are...

Because of difficulties measuring pollution, many prior papers suggest a subsidy to some observable method of reducing pollution. We take three such papers as examples, and we extend each of them to show how welfare under the suggested subsidy can be increased by the addition of an output tax....

Data on tool use from O*Net's Tools and Technologies Supplement can, in conjunction with task-based measures, provide a new proxy for measuring and distinguishing general and specific skills at the occupational level. The tools and types of tools used in an occupation generate reasonable proxies...