Which products, if any, will have a perfectly inelastic demand ? Pick one of the products. How, if at all, could consumers adjust to a rise in the product's price ? Compare the elasticity of demand for that product in the short and long run. Would it change, and of so in what way ? Decide whether you think the product has perfectly inelastic demand. To say it another way, decide whether you think the demand curve will be vertical, or just quite sleep.