CFA1级 经济

Economics

Session 4 Microeconomy

Topics in Demand and Supply Analysis

Demand analysis

Price Sensitivity

Price elasticity 需求Q对价格P变化的敏感程度

分支主题

绝对值＞1 Elastic；绝对值＜1 inelastic

可替代性：越是可被替代，弹性越大

花销：花的越多，对价格越敏感

时间：long-run，弹性越大

必要性 -

Own-price elasticity 自身价格弹性

弹性时：价格下降→总收入上升

非弹性时：价格上升→总收入上升

Cross-price elasticity 两种商品价格与需求的关系

＞0：替代品 substitute 例如：高铁与飞机

＜0：互补品 complements 例如：汽车与汽油

Income elasticity 收入价格弹性

+：正常商品 Normal goods

-：低档商品 inferior goods

Income Effect (有钱了要不要买) vs Substitution Effect (便宜了就多买点)

Giffen 吉芬商品：P下降→Q下降

Veben 韦伯商品：P上升→Q上升 （Veblen虽然有正斜率，但不是inferior商品 例如重奢商品 status goods 不适用于各类效应）

Supply analysis

economic cost and profit

公司的economic profit=0等同于公司获得normal profit

revenue

accounting cost (explicit cost)

accounting profit

implicit cost

economic profit

shutdown and breakdown point

[object Object]

Breakeven point: AR=P=MR=ATC

shutdown point: AR=P=MR=AVC

profit maximization

MR=MC时，利润最大化

long-run average cost curve

The Firm and Market Structures

Perfect Competitive Market 完全竞争

characteristic

key words: large number/identical/few barriers/no pricing power

Monopolistic Competitive 垄断竞争

key words: hybrid market/many competitors/product differentiation/variety/low pricing power(不是no pricing power)

advertising and trademark branding是垄断竞争市场的标志

向下倾斜的需求线，弹性很大

新的公司会进入市场，将旧公司的需求线往左移动，消除economic profit

Oligopoly 寡头

kinked demand model

假设：你提价，竞争者不会跟随；但你要降价，他们会一起降价

nash equilibrium 囚徒困境

影响collusion的因素：
1. the no. and size distribution of sellers 数量规模大→难
2. the similarity of the products 差异性高→难
3. the similarity of cost structure 差异性高→难
4. order size and frequency 金额大，频率低→难
5. the strength and severity of retaliation 报复激烈→难
6. the degree of external competition 越激烈→容易

Stackelberg model

Pre-condition: Dominant firm (DF) 有寡头领导者

长期来看，DB的市场份额会因为新进入的厂商争夺而减少

无法搞价格战

Monopoly 垄断

因为高进入壁垒，可以保持短期/长期的economic profit

资源壁垒 例如Mine

证照管制壁垒

自然壁垒

government interference

方法1：Average cost pricing 平均成本定价 政府强制P=ATC 消除economic profit

方法2：Marginal cost pricing 边际成本定价 P=MC，政府需要补贴subsidy

price discrimination

前提

客户对不同的产品有不同的price elasticties

低价购买的人无法将产品高价再卖出 prevent secondary peddling

1st degree 一级价格歧视——消费者愿意支出的是最高价格
√ consumer surplus =0 厂商拿走了全部消费者剩余 例如 有差别的服务

2nd degree 二级价格歧视——买的越多，价格越低 例如：第二杯半价

3rd degree 三级价格歧视——消费者支付的价格与其特征trait相关 例如：河南老乡半价

Industry concentration measures

N firms concentration ratio ——头部公司市场份额相加

doesn't show the potential entry threat

insensitive by mergers

doesn't consider the elasticity of demand

HHI index——头部公司市场份额平方相加

唯一的不同：对M&A敏感

Session 5 Macroeconomy

Measures of GDP

aggregate output=aggregate income =aggregate expenditure

expenditure approach: GDP=C+I+G+(X-M)

C: Consumer spending on final goods & services

I: Gross private domestic investment

business investment

changes in inventory

G: Government spending

goods and services

fixed investment

X-M

statistical discrepancy

income approach: GDP=C+S+T

S-I=(G-T)+(X-M)

G-T: fiscal balance

+ deficit 赤字

- surplus 盈余

X-M: net exports or trade balance

+ surplus 顺差

- deficit 逆差

value of final output and value added method

直接累计相加

GDP deflator

Nominal GDP (by current prices)

Real GDP (by constant prices)

GDP deflator GDP平减指数

AD and AS curves

IS-LM模型强调商品市场和货币市场之间的相互作用。支出、利率与收入一并在商品市场与资本市场的均衡状态下决定

IS研究的是商品市场，储蓄的变化=投资的变化 S(Y)=I(r)：r与Y呈反向关系

LM研究的是货币市场，货币需求=货币供给 MV=PY：r与Y呈正向关系 Ms/P=Y(剔除了通胀，为实际GDP)

Transaction demand 交易性需求——与GDP正相关

Precautionary demand 预防性需求——与GDP正相关

Speculative demand 投机性需求——与利率负相关

AD-AS模型

AD研究的是总需求：价格P与收入Y呈反向关系

曲线移动就跟财政政策和货币政策相关 只要影响C+I+G+X-M四个因素里面的某一个，就会造成AD线 shift

increase in consumers' wealth 国民财富增加

consumer expectation of future income

business expectations

high capacity utilization

expansionary money policy

expansionary fiscal policy

exchange rate

global economic growth

AS研究的是总供给

VSRAS very short run 完全弹性，产量调整不传递到价格水平

SRAS short-run 价格P与收入Y成正向关系

LRAS long-run 完全非弹性 P不改变Y

macroeconomic equilibrium

long-run full employment

modest stable pool of unemployed workers

short-run recessionary gap

Y2＜Y1
失业率＞自然失业率

do nothing because of self-correcting mechanism→AS线向右移动

宽松的fiscal and monetary policy→AD线往右移

short-run inflationary gap

Y2＞Y1
失业率＜自然失业率

do nothing because of self-correcting mechanism→AS线向左移动

紧缩的fiscal and monetary policy→AD线往左移

short-run stagflation

高通胀、高失业（政府只能择一而治）

Understanding Business Cycles

经济学说

Business cycle

必背

Through

GDP从负到正

失业率→高

通胀→moderate

消费spending→增加

Expansion

GDP 增速accelerate

失业率→快速下降

通胀→适当提高

消费→增加

Peak

GDP 增速下降

失业率→下降，但雇佣率降低

通胀→增加accelerate

消费→放缓

Contraction

GDP负值

失业率提高

通胀率下降，但滞后

消费→下降cutback

unemployment

Frictional 匹配阶段

Structural 淘汰行业

Cyclical 周期性

Full employment 没有周期性失业，但有前两种

Inflation Economic Indicator

indexes used to measure inflation

Laspeyres index 分子→现在P×基年Q；分母→基年P×基年Q

substitution bias 高估实际成本

quality bias

new product bias 无法与时俱进

Paasche index 分子→现在P×现在Q；分母→基年P×现在Q

Fisher index （L×P）^1/2

CPI 消费者角度 vs PPI 生产者角度

Headline inflation 整体通胀 vs core inflation （排除food和energy）

cost push and demand pull

cost-push

increase in money wage rate

increase in the money price of raw material

demand-push

increase in quantity of money

increase in govern purchase

increase in exports

Monetary and Fiscal Policy

Monetary policy

money creation precess

reserve requirement

Money multiplier=1/reserve requirement

Money created=new deposit×Money multiplier=new deposit/reserve requirement

Fisher effect:

monetary policy tools

① open market operations 公开市场操作

buy short-term bond→增加货币供应；反之降低

repurchase agreement→降低货币供应（让银行掏钱）；
reverse repurchase agreement→提高货币供应（给银行放贷）

② policy rate (discount rate) 政策利率/基准利率 商业银行从央行融资的成本

③ reserve requirement 准备金要求 下调将增加货币供应

monetary transmission mechanism

determining the direction of monetary policy

Neutral interest rate 中性利率 =real trend rate of economic growth + inflation target

contractionary monetary policy: policy rate ＞ neutral rate

expansionary monetary policy: policy rate ＜ neutral rate

limitation

liquidity trap 流动性陷阱

央行增加货币供应无法降低短期利率，此时只能祭出quantitative easing 量化宽松

Fiscal policy

argument about national debt

against being concerned

debt is owned internally to fellow citizen

investment projects or enhancing human resource → raising future output and tax

财政赤字会引发tax changes

Ricardian equivalence 财政赤字会引导私人领域提升储蓄，从而提升未来的tax

失业率会降低

being concerned

过高的负债率会大幅提升税收，从而降低经济活动

market lose confidence in a government → print more money → high inflation

crowding out effect 挤出效应 利率上升→将民营从资本市场挤出

limitations of discretionary fiscal policy

recognition lag

action lag

impact lag

determining the direction of fiscal policy

structural budget deficit 结构性赤字——充分就业下的赤字

contractionary fiscal policy : budget deficit ＜ structural budget deficit 政府开支减少，税收增加，赤字降低

expansionary fiscal policy : budget deficit ＞ structural budget deficit 政府开支增加，税收减少，赤字提升

会造成私营领域的crowding out效应

interaction of monetary and fiscal policy

财政政策的工具

Spending tools

Transfer payment 政府调节的工具，左兜转右兜，不计入general spending

current government spending 政府的公共支出，例如教育、卫生、国防；会影响到国家技能水平和overall labor productivity

capital expenditure 政府的基建投入，例如公路、医院、监狱和学校；计入国家GDP，影响国民产值

Revenue tools （税收）

Direct taxes

例如营业税、所得税

Indirect taxes

例如增值税

具有quick implementation和lower additional costs的优势

Fiscal multiplier 衡量政府财政支出和税收对GDP的影响

1/[1-MPC(1-t)]

Session 6 International economy

International Trade and Capital Flows

Absolute adv vs Comparative adv

Abs adv: lower cost or use fewer resources 对比产能

com adv: lower opportunity cost 对比机会成本（A的机会成本=B/A）

Trade Restrictions

objectives of trade and capital restriction

Tariff

Import quota

Export subsidy

VER 自愿出口限制

effects of trade policy

Balance of Payment

Current Acc

Merchandise trade 所有商品

Services 所有服务（旅游、交通及商业）fees from patent and copy right

Income receipts 对外投资收益（非本金）例如外股的分红和利息

Unilateral transfer 单边资产转移（援助、礼品等）

Capital Acc

Capital transfers 债务免除及移民转移资产

Financial Acc

Government-owned assets abroad 黄金、外债、直接对外投资等

Foreign-owned assets in reporting country 本国直接投资、本国债券

cooperation and trade organization

Currency Exchange Rate

FX quotation

d/f 直接报价 vs f/d 间接报价

分子货币为price currency，分母货币为base currecy

real exchange rate

Nominal exchange rate 名义汇率

real exchange rate 实际汇率——考虑了实际购买力

currency regime

dollarization 无本国货币，使用其他货币 例如巴拿马、欧盟

currency board arrangement 法定钉住一个货币

conventional fixed peg arrangement 无法定钉住货币，允许在固定目标浮动=/-1%

pegged exchange rated within horizontal bands 法定钉住一个货币，但可以浮动+/- 2%

Crawling pegs (爬行钉住) 阶段性调整汇率目标

fixed parity with crawling bands 爬行区间固定平价 从固定汇率向浮动汇率过渡

managed float 管理浮动 政府干预下的浮动

independently floating rates 独立浮动 完全市场决定

calculation of Exchange Rate

currency appreciation or depreciation

汇率变动只能针对base currency

cross rate

forward rate

point basis

percentage basis

covered interest rate parity IRP

Interest rate parity利率平价关系

TX and trade balance

Elasticity Approach

对于export和import demand，货币贬值可以改善trade deficit

针对弹性大的商品，例如奢侈品

J curve effect

Absorption approach