## Unit 4: Firms and Markets

1. Discussed today's topics: production function; fixed and variable inputs; long-run versus short-run; total product (TP) curve; marginal product (MP); marginal product of labor; diminishing returns to an input; fixed costs (FC), variable costs (VC), and total costs (TC), FC+VC=TC. Homework: Read pp. 189-197; Problem Set 4.1 (FC, VC, TC) and 4.4 (Daphne's Shop 2)--both due Monday; #1 & 2, p. 203, extra credit. [3/7]

2. Discussed today's topics: marginal costs and average costs (AC); AFC + AVC = ATC; graphing cost curves. Homework: Read pp. 197-202; Answer and Look, #1 and 2, p. 202; Activities 3-2 (MP & MC) and 3-3 (Different Cost Measures of a Firm) are due Friday, 3/21. [3/8]

3. Discussed today's topics: long run ATC curve; economies of scale; diseconomies of scale. Homework: Read pp. 208-213; Answer and Look #1, p. 210; Read pp. 213-220; Activities 3-1 (Different Market Structures) and 3-4 (A Firm's LRTC Curves)--both due Monday. [3/9]

4. Discussed today's topics: price takers; perfectly competitive markets; P = MR =AR; Homework: Read pp. 221-226; Activities 3-5 (Revenue, Profit, & Rules) & 3-6 (Profit Maximization for Perfect Competition)--due Wednesday. [3/12]

5. Took quiz Inputs and Costs. Discussed today's topics: shut-down point; profit decision; AVC & ATC; break-even price; optimal output rule; marginal revenue. Homework: Activity 3-9 (Graphing Perfect Competition)--due Thursday. [3/13]

6. Took quiz on Cost Curves. Discussed today's topics: industry supply curve; short-run market equilibrium; long-run market equilibrium. Homework: read pp. 333-339; answer and look #1, p. 339; Activities 3-7 (SR Equilibrium in Perfect Competition) and 3-8 (LR Equilibrium in Perfect Competition), both due on Friday; extra credit, #10 and #12, p. 229. [3/14]

7. Took quiz on Perfect Competition. Discussed today's topics: monopolists; market power; barriers to entry; natural monopolies; and government monopoly. Homework: read pp. 339-352; answer and look #1 & 2, p. 347; answer and look #1 & 3, p. 352; Activities 3-10 (Revenue Functions of a Monopoly) and 3-12 (Price Discrimination), both due March 29th, the day we come back from Spring Break. Extra credit: Activities 33 (Pure Monopoly) and 34 (Monopoly Pricing) [3/15]

Happy St. Patrick's Day!

8. Discussed today's topics: monopolist's demand curve; MR & TR; profit and welfare effects; public policy; public ownership and regulation; single-price monopoly; perfect price discrimination. Homework: read pp. 352-358; read pp. 363-370; answer and look #1. p.369; Activities 3-11 (Profit Maximization), 3-14 (Regulating a Monopoly), 3-13 (Price Discrimination), and 3-15 (Comparing Perfect Competition and Monopoly), all due Tuesday, March 29th. [3/19]

9. Discussed today's topics: oligopoly; imperfect competition; duopoly; collusion; cartels; 4-firm concentration ratio; HHI. Homework: read pp. 371-378; answer and look #1 & 2, p. 378; Answer #4-6, pp. 385-386, due Tuesday; extra credit, Activity 46 (Kinked Demand Curve of an Oligopolist). [3/20]

10. Discussed today's topics: interdependence; game theory; Nash equilibrium; payoff matrix; prisoners' dilemma; dominant and dominated strategies; tacit collusion; price wars; price leadership; non-price competition; cartels. Homework: Read pp. 379-84, 388-393; Activity 3-17 (Game Theory), which is due Thursday. [3/21]

11. Discussed today''s topics: monopolistic competition; non-price discrimination; product differentiation; short-run v. long-run; zero-profit equilibrium. Homework: Read pp. 393-397, 398-403; Answer #9 & 10, p 387; and Activity 3-16 (Monopolistic Competition), which is due Friday. [3/22]

12. Discussed today's topics: marginal cost and average total cost; excess capacity; advertising; brand names. Took quiz on the different cost curves all four types of firms use to make decisions. Extra credit: Activity 42 (Market Structures and Business Decision Making). [3/23]

13. Reviewed for Unit 4 Exam (Firms and Markets). [4/2]

14. Took free response portion of the Unit 4 Exam. Multiple-choice portion tomorrow. All late work due by tomorrow evening, too. [4/3]

15. Took multiple-choice portion of the Unit 4 Exam. Homework: Read pp. 281-284; Answer and look #1, p. 284. [4/5]

2. Discussed today's topics: marginal costs and average costs (AC); AFC + AVC = ATC; graphing cost curves. Homework: Read pp. 197-202; Answer and Look, #1 and 2, p. 202; Activities 3-2 (MP & MC) and 3-3 (Different Cost Measures of a Firm) are due Friday, 3/21. [3/8]

3. Discussed today's topics: long run ATC curve; economies of scale; diseconomies of scale. Homework: Read pp. 208-213; Answer and Look #1, p. 210; Read pp. 213-220; Activities 3-1 (Different Market Structures) and 3-4 (A Firm's LRTC Curves)--both due Monday. [3/9]

4. Discussed today's topics: price takers; perfectly competitive markets; P = MR =AR; Homework: Read pp. 221-226; Activities 3-5 (Revenue, Profit, & Rules) & 3-6 (Profit Maximization for Perfect Competition)--due Wednesday. [3/12]

5. Took quiz Inputs and Costs. Discussed today's topics: shut-down point; profit decision; AVC & ATC; break-even price; optimal output rule; marginal revenue. Homework: Activity 3-9 (Graphing Perfect Competition)--due Thursday. [3/13]

6. Took quiz on Cost Curves. Discussed today's topics: industry supply curve; short-run market equilibrium; long-run market equilibrium. Homework: read pp. 333-339; answer and look #1, p. 339; Activities 3-7 (SR Equilibrium in Perfect Competition) and 3-8 (LR Equilibrium in Perfect Competition), both due on Friday; extra credit, #10 and #12, p. 229. [3/14]

7. Took quiz on Perfect Competition. Discussed today's topics: monopolists; market power; barriers to entry; natural monopolies; and government monopoly. Homework: read pp. 339-352; answer and look #1 & 2, p. 347; answer and look #1 & 3, p. 352; Activities 3-10 (Revenue Functions of a Monopoly) and 3-12 (Price Discrimination), both due March 29th, the day we come back from Spring Break. Extra credit: Activities 33 (Pure Monopoly) and 34 (Monopoly Pricing) [3/15]

Happy St. Patrick's Day!

8. Discussed today's topics: monopolist's demand curve; MR & TR; profit and welfare effects; public policy; public ownership and regulation; single-price monopoly; perfect price discrimination. Homework: read pp. 352-358; read pp. 363-370; answer and look #1. p.369; Activities 3-11 (Profit Maximization), 3-14 (Regulating a Monopoly), 3-13 (Price Discrimination), and 3-15 (Comparing Perfect Competition and Monopoly), all due Tuesday, March 29th. [3/19]

9. Discussed today's topics: oligopoly; imperfect competition; duopoly; collusion; cartels; 4-firm concentration ratio; HHI. Homework: read pp. 371-378; answer and look #1 & 2, p. 378; Answer #4-6, pp. 385-386, due Tuesday; extra credit, Activity 46 (Kinked Demand Curve of an Oligopolist). [3/20]

10. Discussed today's topics: interdependence; game theory; Nash equilibrium; payoff matrix; prisoners' dilemma; dominant and dominated strategies; tacit collusion; price wars; price leadership; non-price competition; cartels. Homework: Read pp. 379-84, 388-393; Activity 3-17 (Game Theory), which is due Thursday. [3/21]

11. Discussed today''s topics: monopolistic competition; non-price discrimination; product differentiation; short-run v. long-run; zero-profit equilibrium. Homework: Read pp. 393-397, 398-403; Answer #9 & 10, p 387; and Activity 3-16 (Monopolistic Competition), which is due Friday. [3/22]

12. Discussed today's topics: marginal cost and average total cost; excess capacity; advertising; brand names. Took quiz on the different cost curves all four types of firms use to make decisions. Extra credit: Activity 42 (Market Structures and Business Decision Making). [3/23]

**Spring Break! See you back on April 2nd.**13. Reviewed for Unit 4 Exam (Firms and Markets). [4/2]

14. Took free response portion of the Unit 4 Exam. Multiple-choice portion tomorrow. All late work due by tomorrow evening, too. [4/3]

**Teach**-**In about the Year 1968. Part 2 of Unit 4 Exam delayed until tomorrow.**15. Took multiple-choice portion of the Unit 4 Exam. Homework: Read pp. 281-284; Answer and look #1, p. 284. [4/5]