Demand Uncertainty, Incomplete Markets, and the Optimality of Rationing

When the arrival of traders at the market is stochastic, and it is impossible for traders who might arrive to meet ex ante, then Walrasian spot-market clearing presents consumers with price-risk and is typically not Pareto optimal. Instead, with an indivisible good and a divisible numeraire, the first-best can be achieved by an “Exchange” selling raffle tickets at a fixed price. When only spot market trading is feasible and consumers cannot commit to pay unless they purchase the indivisible good, efficiency implies price-fixing with rationing. Potential disadvantages of black markets and scalping are discussed.Journal of Economic LiteratureClassification Numbers: D45, D52, D8.