Consider the market for ride services. About 10 years ago Uber burst onto the scene, followed by Lyft and both competing with existing taxis. Draw two markets -- taxis and ride-share services (Uber, Lyft, etc.). Are they substitutes or complements? As ride-sharing grows, how is the taxi-ride market affected? Draw this effect on your graph and describe what you did. Where is the new equilibrium with respect to the original equilibrium?