A sizeable number of papers beginning with Roberts and Spence (1976) have studied the use of price floors and ceilings (or "collars") to manage prices in tradable permit markets. In contrast, economists have only recently begun examining polices to manage quantities under a pollution tax....

On efficiency grounds, the economics community has to date tended to emphasize price-based policies to address climate change -- such as taxes or a "safety-valve" price ceiling for cap-and-trade -- while environmental advocates have sought a more clear quantitative limit on emissions. This paper...

Carbon markets are substantial and they are expanding. There are many lessons from experiences over the past eight years: fewer free allowances, better management of market-sensitive information, and a recognition that trading systems require adjustments that have consequences for market...