ECES905205 pertemuan 3
2022-09-12
We’ve learned how trade gains both parties
Today we learn why trade is unpopular to some:
How trade generate winners and losers in the short run
Why, despite generating losers, trade is still good.
2 Sectors i: Cloth (C) and Food (F)
3 factor j: Labor (L), Terrain (T), and Capital (K).
How does the economy’s mix of output change as labor is shifted from one sector to the other?
When labor moves from food to cloth, food production falls while output of cloth rises.
The shape of the production function reflects the law of diminishing marginal returns.
Adding one worker to the production process (without increasing the amount of capital) means that each worker has less capital to work with.
Therefore, each additional unit of labor adds less output than the last.
This is not like ricardian where production function is linear and MPL is constant.
If an autarky wants to increase \(Q_C\) by 1 unit, it has no choice but to get labor from industry \(F\)
However, changes in labor affects production differently in different starting point.
If \(L_C\) goes up by 1, \(Q_C\) goes up by \(MPL_C\), which is decreasing as \(L_C\) keeps on increasing.
And while \(L_F\) goes down by 1, \(Q_F\) goes down by \(MPL_F\), which is increasing as \(L_F\) keeps on decreasing.
In other words, to increase \(Q_C\) by 1 unit, \(Q_F\) must go down by \(\frac{MPL_F}{MPL_C}\)
\[ \text{opportunity cost}_C=-\frac{MPL_F}{MPL_C}=\text{Slope of PPF} \]
Why is the production possibilities frontier curved?
Diminishing returns to labor in each sector cause the opportunity cost to rise when an economy produces more of a good.
Opportunity cost of cloth in terms of food is the slope of the production possibilities frontier—the slope becomes steeper as an economy produces more cloth.
In each sector, employers will maximize profits by demanding labor up to the point where the value produced by an additional hour equals the marginal cost of employing a worker for that hour.
A profit maximizing firms will want to employ until:
\[ MPL_C \times P_C = W \]
Note that \(L\) is fixed. Left is C, right is F.
Trade leads to changes in relative price: previously set by local demand endogeneously, now is exogenously given by the global market.
What happens to the allocation of labor and the distribution of income when the prices of food and cloth change?
Two cases:
Now what if the global market price \(P_C\) 10% more than the local market while \(P_F\) remains the same?
When only \(P_C\) rises, labor shofts from the food sector to the cloth sector and the output of cloth rises while that of food falls.
W does not rise as much as \(P_C\) since cloth employment increases hence \(MPL_C\) falls.
\[ \Delta P_C > \Delta w > \Delta P_F \]
\[ \frac{w}{P_C} < \frac{w}{P_F} \]
Labors gain depends on their preference:
if C dominates their expenditure basket, then they lose.
If F dominates their expenditure basket, then they gain.
Specific factor owners are conclusive.
Trade benefits the factor that is specific to the export sector of each country but hurts the factor specific to the import-competing sectors, with ambiguous effect on mobile factors.
With no trade, then we must produce what we consume. That is:
\[ D_C=Q_C \ and \ D_F=Q_F \]
\[ P_C \times D_C + P_F \times D_F = P_C \times Q_C + P_F \times Q_F \]
A bit of algebra to get:
\[ D_F - Q_F = \left(\frac{P_C}{P_F}\right) \times (Q_C-D_C) \]
That is, import of F equals relative price times export of C
How much we import depends on how much we export.
Understand that trade allows for bundles of options.
There’s always better allocation with trade.
If there’s always a better allocation, then the gain for gainers is larger than the loss for losers.
International trade shifts the relative price of cloth to food, so factor prices change.
Trade benefits the factor that is specific to the export sector of each country, but hurts the factor that is specific to the import-competing sectors.
Trade has ambiguous effects on mobile factors.
Trade benefits a country by expanding choices.
Possible to redistribute income so that everyone gains from trade. Those who gain from trade could compensate those who lose and still be better off themselves.
That everyone could gain from trade does not mean that they actually do—redistribution usually hard to implement.
Trade often produces losers as well as winners.
Optimal trade policy must weigh one group’s gain against another’s loss.
Some groups may need special treatment because they are already relatively poor (e.g., Indonesian farmers).
Typically, those who gain from trade are a much less concentrated, informed, and organized group than those who lose.
Governments can provide a “safety net” of income support to cushion the losses to groups hurt by trade (or other changes).
Most economists strongly favor “free” trade.
it is efficient, even if we include mitigation policies.
changes in prices and welfare happens all the time, even without trade.
Trade shifts jobs from import-competing to export sector.
How much unemployment can be traced back to trade?
Substantial political pressure to protect import-competing sectors, even if leads to aggregate losses.
The Trump administration enacted a vast set of tariffs on solar panels, washing machines, steel, aluminium, and an expanding list of manufactured good produced in China.
Many of the protected sectors contained a high proportion of intermediate goods imported by U.S. producers, harming jobs in these downstream sectors.
Retaliation by trading partners had a negative impact on employment by U.S. exporters.