AVERAGE VARIABLE COST: Total variable cost per unit of output, found by dividing total variable cost by the quantity of output. Average variable cost, abbreviated AVC, decreases with additional production at relatively small quantities of output, then eventually increases with relatively larger quantities of output. This pattern is illustrated by a U-shaped average variable cost curve. The logic behind this decrease-increase U-shaped pattern can be found with a closer examination of the law of diminishing marginal returns, average product, and the average-marginal rule. You should also check out marginal cost. See also | total variable cost | short-run production | average variable cost curve | average product | quantity | technology | resource prices | average total cost | marginal cost | average fixed cost | law of diminishing marginal returns | average-marginal rule | U-shaped cost curves | increasing marginal returns | decreasing marginal returns |