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The Daily Insight

What happens when the price of a variable input increases?

Author

James Craig

Published Feb 18, 2026

An increase in the price of the variable input results in the AVC (average variable cost), ATC (average total cost) and MC (marginal cost) moving up together. The curves retain their shape and relative orientation.

What happens to total fixed and total variable costs as production increases?

Since fixed costs do not change as output changes, the total fixed cost line is flat at the level of fixed cost. If no production takes place, variable costs are zero. As production increases, total variable costs increase at a decreasing rate, since the marginal product for each additional worker is increasing.

Why does total variable cost increase?

A variable cost is a corporate expense that changes in proportion to how much a company produces or sells. Variable costs increase or decrease depending on a company’s production or sales volume—they rise as production increases and fall as production decreases.

Why does the MC curve increase?

It is the cost of the variable input. The total cost of producing a given quantity of output is the sum of the fixed cost and the variable cost of producing that quantity of output. The total cost curve becomes steeper as more output is produced due to diminishing returns.

When total product is increasing at an increasing rate?

If the total product curve rises at an increasing rate, the marginal product of labor curve is positive and rising. If the total product curve rises at a decreasing rate, the marginal product of labor curve is positive and falling.

What is a fixed input example?

Fixed inputs are those that can’t easily be increased or decreased in a short period of time. In the pizza example, the building is a fixed input. Once the entrepreneur signs the lease, he or she is stuck in the building until the lease expires. Fixed inputs define the firm’s maximum output capacity.

Is fuel a fixed input?

Fixed Inputs :- They are the inputs whose quantity is constant for some period of time or constant for short run production function. Variable Inputs :- These are inputs whose quantity can vary, even in the short run or for short period of time. Example of these input are labor energy fuel etc.

What is the average product of an input?

It is defined as the output per unit of factor inputs or the average of the total product per unit of input and can be calculated by dividing the Total Product by the inputs (variable factors). Average Product = Total Product/ Units of Variable Factor Input.

Why is cost curve in shape?

The average cost curve is u-shaped because costs reduce as you increase the output, up to a certain optimal point. From there, the costs begin rising as you increase the output.

What is total variable cost curve?

TOTAL VARIABLE COST CURVE: A curve that graphically represents the relation between total variable cost incurred by a firm in the short-run production of a good or service and the quantity produced. The slope of this total variable cost curve is marginal cost.