Answer: Social influence
Explanation:
The reservation price is the maximum price that a buyer is willing to pay for a product. For a consumer, the difference in the reservation price and the agreed price that the buyer finally pay for the product is the consumer surplus.
Social influence is a factor that affects ones reservation price. As individuals, social forces influences our demand. The cost of producing the product is a supply-side factor that will affect the supply but will not affect the reservation price. The price of the good also does not affect the reservation price.