In short-run cost analysis, we examine the cost structure of a firm over a period during which some factors of production are fixed, while others remain variable. The key cost components include total cost, fixed cost, average cost, variable costs, and marginal cost.
- Total Cost (TC): Total cost (TC) represents the overall cost incurred by a firm to produce a certain level of output. It includes both fixed and variable costs. Mathematically, total cost can be expressed as the sum of fixed costs (FC) and variable costs (VC):
TC = FC + VC
- Fixed Cost (FC): Fixed costs are expenses that do not vary with the level of output produced in the short run. These costs remain constant, regardless of whether the firm produces more or fewer units. Examples of fixed costs include rent for the factory building, insurance premiums, and administrative salaries.
- Average Cost (AC): Average cost (AC) is the cost per unit of output produced. It is calculated by dividing total cost (TC) by the quantity of output (Q):
AC = TC / Q
Average cost provides insights into the efficiency of production at different output levels. It is also known as unit cost.
- Variable Cost (VC): Variable costs are expenses that change with the level of output produced in the short run. As production increases, variable costs increase, and as production decreases, variable costs decrease. Examples of variable costs include raw materials, direct labor wages, and energy costs.
- Marginal Cost (MC): Marginal cost (MC) represents the additional cost incurred by producing one additional unit of output. It is the change in total cost resulting from a change in output quantity. Mathematically, marginal cost is calculated as the derivative of total cost with respect to output (Q):
MC = dTC / dQ