The regulation of markets with interdependent demands

We examine the regulatory design of a market for products with interdependent demands, where regulated firms provide (imperfect) substitutes and can engage in lobbying activities. Under centralized regulation, a single regulator is established, whose mandate is to maximize aggregate welfare. Under decentralized regulation, each firm is assigned to a regulator charged with maximizing the welfare generated by that firm. With asymmetric cost information, centralized regulation results in a negative externality between firms when engaging in lobbying. Decentralized regulation removes this externality and reduces lobbying. Since this benefit comes at the cost of miscoordination between regulators, a trade-off results which favors decentralized regulation when goods are substitutes enough.