


政府政策限制或鼓勵移民將影響勞動力之供給
美國主要政策改變,使得移民人數在1965年後增加
移民人數
從1965年250,000
到2000年超過1,000,000
移民對本地(native-born)勞工的影響

Perfect Substitutes:擁有相同的工作技能並競爭相同類型的工作
Dollars
In the Short-Run: with capital held fixed

Immigration使勞動供給線右移:
薪水下降:從w0 to w1
總就業增加:從 N0 到 E1.


薪水下降願意工作之native worker減少:
從N0 到 N1
Supply
w0
w1
Immigrants “take job away” from natives
N
by reducing the native wage and convincing
some native workers that it is no longer worthwhile
to work
Demand
1
N0
E1
Employment

Complements: 不在相同勞動市場競爭
Immigration makes natives more productive:
Dollars

native worker:
生產力上升使薪水增加:從W0到W1
薪水增加讓原本覺得薪水低不願工作
w
的人出來工作:N0到N1
Supply
1
w0

native worker勞動需求線外移
薪水和就業人數增加
Demand
N0
N1
Employment
(native worker)

Suppose immigrants and native are perfect substitutes
In the Short-Run: immigrants lower the wage but raise the
returns to capital

較低的薪資使廠商擴充資本以增加獲利


Demand curve of labor 右移
重要的是右移多少?
只右移一點,受競爭的勞工仍會收到比原本低的薪資
劇烈右移,the negative wage effects might disappear


Immigration 使 the labor supply curve 外移
薪資下降:從 w0 到 w1.
Over time, capital expands as firms take advantage of the
cheaper workforce, shifting out the labor demand curve and
restoring the original wage and level of native employment.
Dollars
Supply
w0
w1
Demand
N0
N0 +
Immigrants
Employment

q=AKα L1-α
 r = $1*α AKα-1 L1-α

w = $1*(1-α) AKα L-α
r = αΑ(K/L)α-1
 w = (1-α)Α(K/L)α

1980年馬列爾偷渡事件，有125,000古巴人偷
渡到邁阿密
 The Cubans most were low-skill workers
 大量移民導致邁阿密labor force grew by
7%

Unemployment rate of blacks
 in Miami
8.3 -> 9.6 +1.3
in comparison
10.3->12.6 +2.3
可能是那段時間經濟環境惡化
這樣看來the mariel flow 還減低了邁阿密地區
的失業成長率for1%

Unemployment rate of blacks
 in Miami
10.1 -> 13.7 +3.6
in comparison
11.5->8.8 -2.7

(a)inceased immigration doesn’t affect the wage ,the SR demand
curve is prrfectly elastic
 (a)inceased in the minimum wage doesn’t affect the
employment ,the SR demand curve is prrfectly inelastic

Dollars
Dollars
D
Demand curve implied by
minimum wage natural
experiment
Demand curve implied by
Mariel natural experiment
w*
D
Employment
(a) Mariel
E*
(b) NJ-Pennsylvania
minimum wage
Employment
在假設中,移民潮會對本地黑人工人造成很大
衝擊
 但是事實證明其實沒有什麼太大影響

The minimum wage increase in New
Jersey 原本假定就業率會比沒實施最低工資
的地區相對下降
 但是結果證明最低工資的實施對就業率沒影
響

The mariel
 △w=α △E+other variables
 New Jersey minimum wage
 △E=β △w+other variables
 There is zero correlation between the
dependent variables and independent
variables ,so the coefficientα ,βis
nearly=0

結
 The immigration induced changes in
supply have little impact on wage
 The increase in minimum wage has little
impact on employment

Dollars
Dollars
S0
S0
S2
S3
S1
PLA
PPT
w0
w0
w*
w*
wLA
Demand
Demand
Employment
Employment
(a) Los Angeles
(b) Pittsburgh
2 variables :
Wage growth for a skill group of native
working man over a particular decade
(1960~2000)
To
非本地勞工的變動量
 負相關
 資料顯示:skill worker immigration
increase10% the wage falls 3~4%
