When total utility decreases, marginal utility is :

Question

Accepted Answer

When total utility decreases, marginal utility is negative. This is because marginal utility refers to the additional utility gained from consuming one more unit of a good or service. If consuming an additional unit leads to a decrease in total utility, it indicates that the marginal utility of that unit is negative. This situation typically occurs when consumption surpasses a certain level, leading to dissatisfaction or a negative experience, such as overeating.

Let's examine why the other options are incorrect:

1. **Zero**: If marginal utility were zero, it would mean that consuming an additional unit neither increases nor decreases total utility. In this case, total utility would remain constant, not decrease. Therefore, zero marginal utility does not explain a decrease in total utility.

2. **Positive**: If marginal utility were positive, consuming an additional unit would increase total utility. This contradicts the scenario where total utility is decreasing, so positive marginal utility cannot be the correct explanation.

4. **None of these**: This option suggests that none of the given options correctly describe the situation. However, as explained, negative marginal utility accurately accounts for the decrease in total utility, making this option incorrect.

In conclusion, when total utility decreases, it is because the marginal utility of consuming an additional unit is negative, which aligns with Option 3 being the correct answer.