' ... the customer and grocer do not disagree on the value of apples. The trade takes place because of ... difference in apple inventories between the parties.

' ... the customer and grocer do not disagree on the value of apples. The trade takes place because of ... difference in apple inventories between the parties. ' Wrong, and wrong. The trade does not occur due to inventory differences between the parties. For example, I have zero apples in my household inventory and no amount of inventory disparity (grocery store vs my house) causes apple trade to happen with me. Trade happens because each party has a coincidence of wants AND each party values the item differently. Each party believes they are gaining by the trade, so the value of the item is different in the minds of each party.