Perfectly competitive markets are characterized by a. conditions that discourage new firms from entering the market. b. conditions that allow firms to determine how much they wish to produce, without influencing the market price. c. conditions that presume that each firm produces a unique product. d. conditions that force firms to advertise their product heavily, to compete with other producers.

5. profit maximization and shutting down in the short run suppose that the market for polos is a competitive market. the following graph shows the daily cost curves of a firm operating in this market. 0 2 4 6 8 10 12 14 16 18 20 50 45 40 35 30 25 20 15 10 5 0 price (dollars per polo) quantity (thousands of polos) mc atc avc for each price in the following table, calculate the firm's optimal quantity of units to produce, and determine the profit or loss if it produces at that quantity, using the data from the previous graph to identify its total variable cost. assume that if the firm is indifferent between producing and shutting down, it will produce. (hint: you can select the purple points [diamond symbols] on the previous graph to see precise information on average variable cost.) price quantity total revenue fixed cost variable cost profit (dollars per polo) (polos) (dollars) (dollars) (dollars) (dollars) 12.50 135,000 27.50 135,000 45.00 135,000 if the firm shuts down, it must incur its fixed costs (fc) in the short run. in this case, the firm's fixed cost is $135,000 per day. in other words, if it shuts down, the firm would suffer losses of $135,000 per day until its fixed costs end (such as the expiration of a building lease). this firm's shutdown price—that is, the price below which it is optimal for the firm to shut down—is per polo.

When the national economy goes from bad to better, market research shows changes in the sales at various types of restaurants. projected 2011 sales at quick-service restaurants are $164.8 billion, which was 3% better than in 2010. projected 2011 sales at full-service restaurants are $184.2 billion, which was 1.2% better than in 2010. how will the dollar growth in quick-service restaurants sales compared to the dollar growth for full-service places?

(a) what was the opportunity cost of non-gm food for many buyers before 2008? (b) why did they prefer the alternative? (c) what was the opportunity cost in 2008? (d) why did it change?