Give circumstances where the demand for commodity may not fall despite a rise in cost

This leads to abnormal demand curve since a rise in cost of a commodity will lead to increase in price of it even though not always

The circumstances here include

• When the commodity in question is a good of ostentation
• Price expectation
• Ignorance effect
• When the commodity is a giffen (a Giffen good is a product that people consume more of as the price rises and vice versa)
• When the commodity is a necessity
• Presence of habitual consumers such as smoker