shutdown and break-even points

Suppose a firm is losing money. Should it keep its doors open and bleed slowly, or close and stop the bleeding? The surprising answer is that it often pays to keep trading at a loss — for a while. Two special prices mark the turning points: the break-even point and the shutdown point. They tell a struggling firm whether to celebrate, soldier on, or shut the doors.

The break-even point is the output where price exactly equals average total cost — revenue just covers every cost, so economic profit is zero (the firm earns normal profit). Above this price, the firm makes a profit; below it, a loss. The shutdown point is lower: it is where price equals minimum average variable cost. The key insight is that fixed costs (the rent) must be paid whether the firm produces or not, so they are irrelevant to the short-run open-or-close decision. What matters is only the variable cost. If the price covers the average variable cost, every unit sold contributes something toward the unavoidable rent, so it is better to keep going and lose less than the full fixed cost. If the price cannot even cover average variable cost, then producing each unit loses more than just shutting down — the firm should temporarily close, accepting a loss equal to its fixed cost. So: above break-even, profit; between break-even and shutdown, loss but keep producing; below shutdown, close.

These two points capture one of economics' sharpest lessons: sunk and fixed costs should not drive a forward-looking decision. A factory that cost a fortune to build still keeps running on a bad day if the price covers its variable costs, because the building is paid for regardless — looking back at it is a trap. The shutdown rule is short-run; in the long run, even fixed costs become avoidable (the lease ends, equipment can be sold), so a firm earning less than normal profit will eventually exit the industry altogether rather than merely pause.