This paper presents a model of competing payment schemes. Unlike previous work on generic two-sided markets, the model allows for the fact that in a payment system, users on one side of the market (merchants) compete to attract users on the other side (consumers, who may use cards for...

"Market power in electricity wholesale spot markets is more likely if there is market segmentation. We show that principal component analysis is a natural tool for the qualitative and quantitative assessment of the presence of local markets. We study whether the New Zealand market has been a...