古典理论：长期中的经济

Exercise: determine returns to scale
Determine whether each of the following production functions has constant, increasing, or decreasing returns to scale:
a) F (K , L ) 2K 15L
b) F (K , L )
KL
c) F (K , L) 2 K 15 L
Assumptions of the model模型的假设
1. Technology is fixed.
2. The economy’s supplies of capital and
model
Supply side
factor markets (supply, demand, price) determination of output/income
Demand side
determinants of C, I, and G
Equilibrium
goods market loanable funds market
(If z = 1.25, then all inputs are increased by 25%)
If constant returns to scale, Y2 = zY1
If increasing returns to scale, Y2 > zY1
If decreasing returns to scale, Y2 < zY1
Factors of production
K = capital, tools, machines, and structures used in production L = labor, the physical and mental efforts of workers
to keep our model simple
The Wealth of Nations suggested that the economy was controlled by the “invisible hand” whereby the market system, instead of government would be the best mechanism for a healthy economy.
厨房和相关设备是 面包店的资本
用于制作面包的工人 是劳Baidu Nhomakorabea力
面包是产出
The production function
denoted Y = F (K, L)
shows how much output (Y ) the economy can produce from K units of capital and L units of labor.
In this module, we will develop a basic classical model to explain various economic interactions We are going to examine carefully the modern theory of how national income is distributed among the factors of production.
CHAPTER THREE
National Income: Where it Comes From and Where it Goes
在本章，你会学到如下内容:
What determines the economy’s total output/income
How the prices of the factors of production are determined
reflects the economy’s level of technology. exhibits constant returns to scale.规 模报酬不变
如果 Y1 = F (K1 , L1 )
Scale all inputs by the same factor z: K2 = zK1 and L2 = zL1
labor are fixed at
K K
and
L L
In chapters 7 and 8 (Economic Growth I and II), we will relax these assumptions
Determining GDP
Output is determined by the fixed factor supplies and the fixed state of technology:
Y F (K , L )
The distribution of national income determined by factor prices, the prices per unit that firms pay for the factors of production.
How total income is distributed What determines the demand for goods and services
How equilibrium in the goods market is achieved
假设：A closed economy, market-clearing
古典理论：长期中的经济
什么是古典经济理论
It is a quite simple but powerful analytical model built around buyers and sellers pursuing their own self-interest 。 It’s emphasis is on the consequences of competition and flexible wages/prices for total employment and real output 。 Its roots go back to 1776—to Adam Smith’s Wealth of Nations