Economic profit is total revenue minus total costs, where total costs include both explicit costs (money paid out) and implicit costs (opportunity costs like the owner's time or forgone investment returns). In AP Micro, firms respond to economic profit, not accounting profit (EK CBA-2.C.1).
Economic profit is what's left after you subtract everything a firm gives up to operate, not just the bills it pays. Total revenue minus explicit costs (wages, rent, materials) gives you accounting profit. Economic profit goes one step further and also subtracts implicit costs, which are the opportunity costs of resources the firm already owns. Think of the salary the owner could earn elsewhere, the interest their savings could earn, or the compensation they'd need for taking on risk (EK CBA-2.C.2).
Here's the line that makes it click on the exam: a firm earning zero economic profit is not failing. Zero economic profit means the firm is covering all its costs, including opportunity costs, so the owner is doing exactly as well here as in their next-best option. That's called normal profit, and it's why firms in long-run perfect competition stick around even when economic profit is zero. The CED is explicit that firms make decisions based on economic profit, not accounting profit (EK CBA-2.C.1).
Economic profit lives in Topic 3.4 (Types of Profit) under learning objectives AP Micro 3.4.A, 3.4.B, and 3.4.C, where you define it, explain how firms respond to it, and calculate it from graphs or tables. But its real payoff is in Topic 3.7 (Perfect Competition) under AP Micro 3.7.C, because economic profit is the engine of long-run adjustment. Positive economic profit attracts entry, negative economic profit (loss) causes exit, and the market only settles down when economic profit hits zero. If you don't get economic profit, the entire long-run story of Unit 3 falls apart, and so does the comparison to monopoly in Unit 4, where barriers to entry let positive economic profit survive forever.
Keep studying AP Microeconomics Unit 3
Accounting Profit (Unit 3)
Same revenue, different cost line. Accounting profit only subtracts explicit costs, so it's always greater than or equal to economic profit. A firm can show a healthy accounting profit and still be losing money economically if the owner could earn more elsewhere.
Normal Profit (Unit 3)
Normal profit is just zero economic profit wearing a friendlier name. It means implicit costs are fully covered, so the owner has no reason to leave the industry. This is the long-run resting point of perfect competition.
Opportunity Cost (Unit 1)
Economic profit is Unit 1's opportunity cost concept applied to the firm. Implicit costs ARE opportunity costs, so calculating economic profit is really just asking what the firm's resources could have earned in their next-best use.
Barriers to Entry (Unit 4)
Entry is what erodes economic profit in perfect competition. Block entry with a patent or a local monopoly (like the FillUp gas station in the 2019 FRQ) and positive economic profit can persist into the long run. The presence or absence of long-run economic profit is the single fastest way to tell market structures apart.
You need to do three things with economic profit. First, calculate it from a graph or table, usually as (P − ATC) × Q at the profit-maximizing quantity where MR = MC (AP Micro 3.4.C and 3.7.C). Second, predict the long-run response, which is the classic chain: positive economic profit → firms enter → market supply increases → price falls → economic profit returns to zero. Practice questions hit this constantly with stems like "if economic profits are greater than zero, what should we expect in the long run?" Third, use it on FRQs. The 2019 FRQ told you FillUp's monopoly was "earning positive economic profit," the 2022 FRQ did the same with a patent-holding firm, and the 2017 and 2021 FRQs asked about perfectly competitive corn markets where you trace how a demand shock creates short-run profit and how entry eliminates it. On graphing FRQs, be ready to shade the profit rectangle between price and ATC.
Accounting profit is total revenue minus explicit costs only, which is what shows up on a firm's financial statements. Economic profit also subtracts implicit costs (opportunity costs of the owner's time, capital, and risk-taking), so it's always smaller than or equal to accounting profit. The exam trap: a firm with positive accounting profit but negative economic profit should exit the industry, because the owner could do better elsewhere. The CED says firms respond to economic profit, not accounting profit (EK CBA-2.C.1).
Economic profit equals total revenue minus both explicit costs and implicit costs, so it is always less than or equal to accounting profit.
Zero economic profit is normal profit, which means the firm covers all opportunity costs and has no incentive to enter or exit the industry.
Firms make entry, exit, and production decisions based on economic profit, not accounting profit (EK CBA-2.C.1).
In perfect competition, positive economic profit attracts new firms, which increases supply, lowers price, and pushes economic profit back to zero in the long run.
On a graph, calculate economic profit as (price minus ATC) times quantity at the output where MR equals MC.
Long-run positive economic profit only survives when barriers to entry exist, which is what separates monopoly from perfect competition.
Economic profit is total revenue minus total costs, where total costs include both explicit costs (actual payments like wages and rent) and implicit costs (opportunity costs like the owner's forgone salary). It's the profit measure firms actually use when deciding to enter, exit, or keep producing.
No. Zero economic profit means the firm is earning normal profit, covering every cost including the opportunity cost of the owner's time and capital. The owner is doing exactly as well as their next-best alternative, which is why firms stay in perfectly competitive markets even at zero economic profit.
Accounting profit subtracts only explicit costs from revenue, while economic profit also subtracts implicit (opportunity) costs. So economic profit is always less than or equal to accounting profit, and a firm can have positive accounting profit but negative economic profit, which signals it should exit.
Find the profit-maximizing quantity where MR = MC, then compute (price minus ATC) at that quantity and multiply by the quantity. If price is above ATC the firm earns positive economic profit, and if price is below ATC it takes an economic loss.
There are no barriers to entry, so positive economic profit attracts new firms, market supply increases, and price falls until economic profit hits zero. The 2017 and 2021 FRQs both tested this entry-and-adjustment process in perfectly competitive corn markets.