Hi ,consider this as well;
Carrot on a stick is an idiom that refers to a policy of offering a reward for making progress towards benchmarks or goals but not necessarily ever actually delivering. The original metaphor referred to a boy sitting on a cart being pulled by a donkey. The boy held a long stick to which a carrot had been tied, and he dangled the carrot in front of the donkey but just out of its reach. As the donkey moved forward to get the carrot, it pulled the cart—and the boy—so that the carrot always remained just out of reach as the cart moved forward.