This study proposes a tentative model of consumer's decision making in the hoarding panic and presents some evidence that in the present system of goods distribution the hoarding panic is triggered easily by less than 10% of total consumers. The toilet paper hoarding panic in 1973 in Kansai is divided into four sequential stages; precursor, outbreak, expansion, and termination of panic. Four categories of consumers, based on different decision making processes are hypothesized, corresponding with each stage. The early hoarding consumer begins to lay in a large stock from a self-reward maximization motive, anticipating the high rise in price of toilet paper by low credible rumor. The middle hoarding consumer acts by indirect support of the rumor from newspaper accounts. The late hoarding consumer rushes into hoarding from a defensive motive, strongly afraid of life without toilet paper. The no-hoarding consumer with enough stock is also dragged into the tragedy of commons, thus suffering from high price caused by panic.
