Buyers in the market for iPhones learn that the price of the Samsung Galaxy has increased. Explain how this would shift demand in the market for iPhones.

iPhones and Samsung phones can be considered close substitutes, i.e. if the price of one increases, consumers may wish to switch to the cheaper alternative. This means the demand for the substitute will rise. In this particular case, as the price for Samsung phones increases, the demand curve for iPhones is likely to shift outwards/to the right.