Firms in competitive markets

Firms in competitive marketsPrepared by: Ms. Dang GannabanWHAT IS A COMPETITIVE MARKET?COMPETITIVE MARKET a market with many buyers and sellers trading identical products so that each buyer and seller is a price taker.Three CHARACTERISTICS:There are many buyers and sellers in the market.The goods offered by the various sellers are largely the same.Firms can freely enter or exit the market.

THE REVENUE OF A COMPETITIVE FIRMQUANTITY(Q)PRICE(P)TOTAL REVENUE(TR = P x Q)AVERAGE REVENUE(AR = TR / Q)MARGINAL REVENUE(MR = TR / Q)1 gallon$6$6$66261266361866462466563066663666764266864866AVERAGE REVENUE total revenue divided by the quantity sold.

MARGINAL REVENUE the change in total revenue from an additional unit sold.

Quick Quiz:When a competitive firm doubles the amount it sells, what happens to the price of its output and its total revenue?PROFIT MAXIMIZATION AND THE COMPETITIVE FIRMS SUPPLY CURVE

MAXIMIZATION: A NUMERICAL EXAMPLEQTRTCPROFIT(TR-TC)MRMCCHANGE IN PROFIT(MR MC)O gallons$0$3-$3$6$2$416516332128464231812665142417766053023767-163630668-274238469-38484716THREE GENERAL RULES FOR PROFIT MAXIMIZATION:If marginal revenue is greater than marginal cost, the firm should increase its output.If marginal cost is greater than marginal revenue, the firm should decrease its output.At the profit-maximizing level of output, marginal revenue and marginal cost are exactly equal.THE FIRMS SHORT-RUN DECISION TO SHUT DOWNSHUT DOWN refers to a short-run decision not to produce anything during a specific period of time because of current market conditions.EXIT refers to a long-run decision to leave the market

Shut down if TR < VCShut down if TR/Q < VC/QShut down if P < AVCSUNK COST a cost that has already been committed and cannot be recovered.THE FIRMS LONG RUN DECISION TO EXIT OR ENTER A MARKETExit if TR < TC

Exit if TR/Q < TC/Q

Exit if P < ATC

Enter if P > ATC 11SUMMARY:Because a competitive firm is a price taker, its revenue is proportional to the amount of output it produces. The price of the good equals both the firms average revenue and its marginal revenue.To maximize profit , a firm chooses a quantity of output such that marginal revenue equals marginal cost. Because marginal revenue for a competitive firm equals the market price, the firm chooses quantity so that price equals marginal cost. Thus, the firms marginal cost curve is its supply curve.SUMMARY:In the short run when a firm cannot recover its fixed costs, the firm will choose to shut down temporarily if the price of good is less than average variable cost. In the long run when the firm can recover both fixed and variable costs, it will choose to exit if the price is less than average total cost.

In a market with free entry and exit, profits are driven to zero in the long run. In this long-run equilibrium, all firms produce at the efficient scale, price equals the minimum of average total cost, and the number of firms adjusts to satisfy the quantity demanded at this price.