大二上学习宏观各章课件

1、CHAPTER THREENational e:Where it Comes From and Where it Goesslide 1In this chapter you will learn:what determines the economys total ehow the prices of the factors of production are determinedhow total e is distributedwhat determines the demand for goods and serviceshow equilibrium in the goods mar

2、ket is achievedslide 2Outline of modelA closed economy, market-clearing modelSupply sidefactor markets (supply, demand, price)determination of eDemand sidedeterminants of C, I, and GEquilibriumgoods marketloanable funds marketslide 3Factors of productionK = capital, tools, machines, and structures u

3、sed in productionL = labor, the physical and mental efforts of workersslide 4The production functiondenoted Y = F (K, L)shows how much output (Y ) the economy can produce fromK units of capital and L units of labor. reflects the economys level of technology. exhibits constant returns to scale.slide

4、5Returns to scale: a reviewInitially Y1 = F (K1 , L1 ) Scale all inputs by the same factor z: K2 = zK1 and L2 = zL1 (If z = 1.25, then all inputs are increased by 25%)What happens to output, Y2 = F (K2 , L2 ) ? If constant returns to scale, Y2 = zY1 If increasing returns to scale, Y2 zY1 If decreasi

5、ng returns to scale, Y2 G , budget surplus = (T G ) = public savingWhen T 0big tax cuts: T 0According to our model, both policies reduce national saving:slide 491. The Reagan deficits, cont.rS, II (r )r1I1r22.which causes the real interest rate to riseI23.which reduces the level of investment.1.The

6、increase in the deficit reduces savingslide 50Are the data consistent with these results?variable1970s1980sT G2.23.9S19.617.4r1.16.3I19.919.4TG, S, and I are expressed as a percent of GDPAll figures are averages over the decade shown.slide 51Now you tryDraw the diagram for the loanable funds model.

7、Suppose the tax laws are altered to provide more incentives for private saving. What happens to the interest rate and investment? (Assume that T doesnt change)slide 52Mastering the loanable funds model2. Things that shift the investment curvecertain technological innovations to take advantage of the

8、 innovation, firms must buy new investment goodstax laws that affect investmentinvestment tax creditslide 53An increase in investment demandAn increase in desired investmentrS, II1I2r1r2raises the interest rate.But the equilibrium level of investment cannot increase because thesupply of loanable fun

9、ds is fixed.slide 54Saving and the interest rateWhy might saving depend on r ?How would the results of an increase in investment demand be different?Would r rise as much?Would the equilibrium value of I change?slide 55An increase in investment demand when saving depends on the interest rateslide 56C

10、hapter summaryTotal output is determined byhow much capital and labor the economy hasthe level of technologyCompetitive firms hire each factor until its marginal product equals its price. If the production function has constant returns to scale, then labor e plus capital e equals total e (output).sl

11、ide 57Chapter summaryThe economys output is used forconsumption (which depends on disposable e)investment (depends on the real interest rate)government spending (exogenous)The real interest rate adjusts to equate the demand for and supply ofgoods and servicesloanable fundsslide 58Chapter summaryA decrease in national saving causes the interest rate to rise and investment to fa