平狄克 微观经济学 第七版 课件 第一章

11Examples of Social Problems•Rent of apartments in Xiamen is too high–set a ceiling on rent•Women’s wages are lower than men’s–adopt “equal pay” policy•Medical cost is too high–government provides subsidies•Domestic steel producers are threatened by competition from imports–impose tariffs•Too many drug addicts–toughen narcotic law enforcement2Whatis Microeconomics?•Microeconomicsstudies the behaviorand interactionof individual decision-making agentsbyfocusing on their objectivesandthe constraintsthey face

3The Economics Approach•To understand human behavior, an economist tries to identify and focus on:–people’s objectives or interests•What do they want to pursue?•What incentives do they face? –strategies or choices available (to further interests)–constraints to choices•Cannotget everything =>tradeoffs–how people’s decisions interact with each other’s•Outcome of the interaction as an equilibrium4Allocation of Resources•Three main questions about allocation of resources:–what to produce? –how to produce? –who gets the products?•Answers to the above questions in:–Robinson Crusoe–a small tribe–a modern economy

5From Individuals to a Market Economy•Decision-making agents:–individuals (consumers, workers, investors, owners of resources, etc), firms, governments•Individual economic units together form industries and markets•In a market economy, demand, supply, competition in market=> market prices=> allocation of resources6About Economic Theory•Theory (Model) and Prediction–a theory is like a story—how one thing leads to another–a theory is useful if its predictions are correct–using simple theories to explain (parts of) a complicated world

•Positive Economics and Normative Economics–“Is” versus “Ought”•Micro-and Macro-economics2

7*Most Important to Know *•Opportunity cost–the bestalternative given up in order to pursue a choice•Consider the costs and benefits relevantto a choice–costs and benefits that occur as a resultof an action–for a decision about extent, think at themargin:•marginalbenefit andmarginal cost; or•marginalbenefits between alternatives8Basicsof Demand and Supply•demand curve•supply curve•market mechanism•equilibrium (price and quantity)

9The Demand Curve•Demand Curve–the relationship between the quantity of a good that consumers want tobuy and the price of the good–quantity on the x-axis; price on the y-axis–Quantity demanded vs. Demand)(DDPQQ=10The Demand CurveDQuantity

Price($ per unit)

P1

Q1

P2

Q2

Law of Demand:The demand curve slopes downward –consumers buy more as the product becomes cheaper

11FactorsAffecting Demand•income•pricesof related goods–complements–substitutes•change in taste of consumers•expectation of future prices12Change in Demand(income increases)

DQuantity

Price($ per unit)

P1

Q1

P2

Q2

D’3

13Quantity Demanded vs. Demand•Changes in quantity demanded–movements along the demand curve caused by a change in price–(P1,Q1) to (P2,Q2) along D•Changes in demand –a shift of the entire demand curve caused by factors other than price•Income•Change in preferences14The Supply Curve•Supply Curve–the relationship between the quantity of a good that producers want tosell and the price of the good

–quantity on the x-axis; price on the y-axis

–Quantity supplied vs. Supply)(SSPQQ=

15The Supply CurveSLaw of Supply:The supply curve slopes upward –firms increase output as the price goes upQuantityPrice($ per unit)P1Q1P2Q216FactorsAffecting Supply•Costs of Inputs–inputs to production: labor, capital, land, raw materials, etc

–lower costs of production cause a firm to want toproduce more

•Change in production technology

17Shift in Supply(costof an input falls)SQuantityP($ per unit)P1Q1P2Q2S’18Quantity Supplied vs. Supply•Change in Quantity Supplied–movement along the curve caused by a change in price

–(P1,Q1) to (P2,Q2) along S•Change in Supply–shift of the curve caused by a change in factors other than the price of the good

•Costs of inputs to production•Production technology