Final answer:
Banning soda in vending machines potentially reduces consumption by increasing the opportunity cost of obtaining it, leading to a substitution effect with alternative beverages and influencing healthier choices.
Step-by-step explanation:
Using the concept of opportunity cost, the ban on the sale of soda in vending machines can be thought to reduce consumption because it increases the cost (not necessarily monetary) for students to obtain soda.
The opportunity cost in this case is the time, effort, or money a student would have to spend to get soda from another source. When soda is easily accessible, the opportunity cost is low, making it a more appealing choice.
With a ban, the opportunity cost rises, and students might decide it's not worth the extra effort or cost to obtain soda elsewhere, potentially leading to a decrease in overall consumption.