Macroeconomics 1st Edition by Dean Karlan,Jonathan Morduch

Exercise 28

Suppose you are at a flea market and are considering buying a box of vintage records. You are trying to bargain down the price, but the seller overhears you telling a friend that you are willing to pay up to $50. Why is your consumer surplus now likely to be lower than it would have been if the seller hadn't overheard you?