The introduction of an income tax as in the previous statement will induce a worker to work more.

The indifference curves of a workaholic are extremely steep.

Suppose the government taxes labour income at a rate of 20%. As a result the worker’s marginal rate of transformation decreases.

After his heart attack, Luis came to realize that he should enjoy life more. His indifference curves became steeper.

Continuation of the previous statement. The opportunity cost of a free day decreases as a result of the rent Frank receives.

Frank inherits a house from his aunt that he rents out, which provides him with an extra monthly income on top of his income from work. He will reach a new optimum where his utility definitely increases.