What type of costs do not change when the level of output changes?

Fixed costs are expenses that remain constant regardless of the level of output produced by a firm. These costs do not fluctuate with production levels and are incurred even if no goods are being produced. Examples of fixed costs include rent, salaries of permanent staff, and insurance.

In contrast, variable costs change in direct proportion to the level of output. For instance, costs associated with materials and labor can increase as production ramps up. Marginal costs refer to the additional cost incurred from producing one more unit of a good, making them directly variable with output. Average costs are calculated by dividing total costs by the number of units produced, which means they can change as output changes due to the influence of both fixed and variable costs.

Therefore, fixed costs are distinct in their unwavering nature as output varies, which clearly defines them in this context.