The current study points out that the derivation of the aggregate demand curve based on theory of consumer behavior has a fundamental flaw, from which the Giffen product has to be inferior good and has been always regarded as an exception of law of demand is therefore not convincing. The current...

Travel restrictions are often imposed to limit the spread of infectious diseases. As uniform restrictions can be inefficient and incur unnecessarily high costs, this paper examines the optimal design of restrictions that target specific travel routes. We propose a model with trade-offs between...