What is a catalyst? -- Build a catalyst strategy -- Identify the catalyst community -- Establish a pricing structure -- Design the catalyst for success -- Focus on profitability -- Compete strategically with other catalysts -- Experiment and evolve -- Cracking the catalyst code

This essay surveys the economic literature on interchange fees and the debate over whether interchange should be regulated and, if so, how. We consider, first, the operation of unitary payment systems, like American Express, in the context of the recent economic literature on two-sided markets,...