Final answer:
Over the past two decades, consumer tastes have shifted in favor of smartphones, leading to an increase in demand for them and a decrease in demand for landlines. These changes are represented graphically by a rightward shift in the demand curve for smartphones and a leftward shift for landlines, due to factors such as technological advancements and mobile communication preference.
Step-by-step explanation:
The question the student asked is about how changes in consumer tastes and preferences over the past 10–20 years have led to a shift in the demand curves for landline phones and cell phones/smartphones. As consumer preferences shifted towards more versatile and portable communication options, the demand for landline phones has decreased, causing a leftward shift in the demand curve. Conversely, the demand for cell phones and smartphones has significantly increased, leading to a rightward shift in their demand curve.
When graphing these changes, the new demand curve for landlines would be positioned to the left of the original demand curve, indicating lower quantities demanded at each price level. For cell phones and smartphones, the new demand curve would be to the right of the original, showing an increase in quantity demanded at every price level. This shift is a result of advancements in technology, the enhanced functionality of smartphones, and the preference for mobile communication and data services.
Smartphones have also transformed access to services in developing countries, allowing for communication in areas without landlines and providing tools for business and education that were previously unavailable.