Hi, Utility in economics is represented by an indifference curve. Any point on an indifference curve is said to provide an equal amount of utility, or happiness, for a person. Normally, as a person earns more income at a higher wage he/she is likely to decrease working hours to the point where total income likely is close to what it was before the wage increase, yet as the person has decreased work hours, he/she gains free time. In contrast, if there is no wage increase, a person needs to work more hours, but is rewarded by gaining income to the point where he/she can afford all needs. In both cases, a person remains on the same indifference curve for he/she is only exchanging one good for the other to the point where his/her amount of utility or happiness is reached. This means he/she is merely travelling up and down the same utility curve That is how this is shown.