In the first story, obtaining the princess’s golden ball was exchanged for these: love, companionship, the frog being seated at the table, drinking from the princess’s cup, and sleeping in the princess’s bed. An exchange can also be seen in the second story—rampion was exchanged for a daughter. As for the last story, there are two exchanges that occur. The daughter would spin gold for the king in exchange for a change of status. At the same time, the daughter who would become queen exchanges her belongings (her necklace and ring) and her future firstborn child for the spinning of gold.
We could also see that the transactions were done by different types of people. In “The Frog Prince”, an exchange occurred between a daughter and a son. In the other two stories, transactions were made by consenting adults.
What transpires in these exchanges is the possession of the person and the choices she makes. In the first story, a young female is led towards the lack of control of her own self. She has to abide by the promise that she has made to the frog. Although she is unwilling to give up control of herself, she is forced to love and to offer companionship and intimacy to the frog prince. In the second story, it is a female who dominates a couple and a fellow female. A couple has to give up their daughter for rampion. In the third story, the ones who wield power are (a) a king who wishes to obtain a commodity and (b) a magical creature who wants to obtain a firstborn child.
What is apparent in the chosen stories is not just the exchange, but possession and dominion of a person, more specifically, a female and her choices.