Which common saying best captures the concept of incentives, which is one of the foundations of economics?/?

Answer: If the carrot doesn't work, try the stick

Explanation: It is a very common saying for the concept of incentives, where in it says that it is important to change the customers habits by providing them incentives on using the product as the customers' feel reluctant to change as they like at what they are. So the saying says that if the carrot doesn't work, like with normal advertisement doesn't bring change in consumer habits then try the stick, which means provide them incentives for using the product.