An exceptional demand curve can result from

An exceptional demand curve can result from an expectation of future price increase. When people think that the price of a good or service is going to increase in the future, they may start buying more of it now in order to avoid paying the higher price later. This increase in demand can cause the price of the good or service to go up in the present, creating an exceptional demand curve that deviates from the typical downward-sloping demand curve. The other factors, such as an increase in the price of raw materials, increase in the size of the population, or change in taste of consumers, can also impact the demand for a good or service, but an expectation of future price increase is a unique factor that can result in an exceptional demand curve.