Title IV of the Clean Air Act Amendments of 1990 created a market for electric utility emissions of sulfur dioxide (SO2). Recent papers have argued that flaws in the design of the auctions that are part of this market have adversely affected its performance. These papers incorrectly assume that...

Software platforms are a critical component of the computer systems underpinning leading-edge products ranging from third-generation mobile phones to video games. After describing some key economic features of computer systems and software platforms, the paper presents case studies of personal...