Airline travel and train travel in Europe are substitute goods. Suppose the price of airline travel decreases.
1. Explain what happens to the demand curve for airline travel. The demand curve for airline travel would increase because
2. Explain what happens to the demand curve for train travel. (In your explanation, be sure and describe which one is a change in quantity demanded with movement along the demand curve and which one is a change in demand with a shift in the demand curve)