In the light of Marxism, exploitation exists universally in the capitalist society.
Capitalists exploit workers by squeezing the surplus value of workers.
The profit is in fact the surplus of value, which should belong to workers rather than capitalists. However, in a perfect competitive market, it is well known that the economic profit in the long run is zero. Based on this conclusion, I demonstrated in this paper that no exploitation occurs between a capitalist and the workers in perfect competition. This implies that not only the class but also the competition determine whether exploitation exists. Certainly, the reality is not perfect competitive, and probably perfect competition will never come true.