Final answer:
An increase in the price of Ubers results in a rightward shift of the demand curve for Lyft, signaling increased demand for Lyft across all price levels due to the services being substitutable.
Step-by-step explanation:
When the price of Ubers goes up, customers may start looking for alternative transportation methods, such as using Lyft. This would increase demand for Lyft, as the services are substitutable. Consequently, the demand curve for Lyft will shift to the right, indicating that, at every price level, more people are willing to use Lyft than before. This is not a movement along the demand curve, which is what happens with changes in the quantity demanded due to a change in the price of the same good or service. Instead, it's a reactive shift due to changes in the circumstances surrounding a related service or good.
As a visual representation, imagine plotting a new demand curve to the right of the original one, showing increased quantity demanded for Lyft's service at the same price points. This shift is reflective of the elasticity of demand for Lyft, as the percentage change in quantity demanded varies with the change in Uber's prices.