Presentation on theme: "Classic Trade Theory Ricardian Model - Technological Comparative Advantage: Basic 2 Good Ricardian model (Feenstra, Chapter 1) Continuum of Goods [Dornbush,"— Presentation transcript:
1Classic Trade TheoryRicardian Model - Technological Comparative Advantage:Basic 2 Good Ricardian model (Feenstra, Chapter 1)Continuum of Goods [Dornbush, Fischer and Samuelson (1977)]Heckscher-Ohlin Factor Endowment Model:2 Good 2 Factor Model (Feenstra, Chapters 1)Stolper SamuelsonLeontief ParadoxHeckscher-Ohlin-Vanek Model and Tests of HO theory
2Basic Ricardian 2 Good Model We assume country specific technologies in the form of labor requirements: Home [ no *] : aiForeign [*] : ai*The basic model allows 2 goods/ industries, i = 1, 2Labor is exogenous, and mobile across industries: L, L*Markets clear so workers are paid value of marginal product:𝑝 𝑖 = 𝑤 𝑖 𝑎 𝑖The mobility of workers implies that wages equalize across industries:𝑝 1 𝑎 1 = 𝑝 2 𝑎 2Set p2 as the numeraire and denote relative price p:𝑝= 𝑝 1 𝑝 2𝑝= 𝑎 1 𝑎 2
3Economic Output under Autarchy (no trade) Home PPFForeign PPFy2y2*L*/a2*L/a2A*Apapa*L/a1y1L*/a1*y1*L is labor endowmentA is consumption point𝑦 𝑖 is the output of industry I𝑝 𝑎 is the autarchy price
4Technology determines Comparative Advantage Define Relative home productivity: 𝑅 1 = 𝑎 1 ∗ 𝑎 1 Suppose Home has a comparative advantage in good 1: 𝑎 1 𝑎 2 < 𝑎 1 ∗ 𝑎 2 ∗ 𝑝 𝑎 < 𝑝 𝑎∗ 𝑎 1 𝑤 1 < 𝑎 1 ∗ 𝑤 1 ∗ 𝑤 1 𝑤 1 ∗ < 𝑅 1 Comparative advantage is a function of relative wages and technology, but wages are endogenous.
6pRelative Supplype = pa*paRelative Demand(𝐿/ 𝑎 1 )/( 𝐿 ∗ / 𝑎 2 ∗ )(𝑦 1 + 𝑦 1 ∗ )/( 𝑦 2 + 𝑦 2 ∗ )Here the demand for good one is high enough that the equilibrium price of trade is equal to the autarchy foreign priceForeign is no better off with trade.When might this occur?
7Gains from Trade p Relative Supply pa* pe pa Relative Demand (𝐿/ 𝑎 1 )/( 𝐿 ∗ / 𝑎 2 ∗ )(𝑦 1 + 𝑦 1 ∗ )/( 𝑦 2 + 𝑦 2 ∗ )Here the trade price of good one is higher than in autarchy at home, and lower than in autarchy in foreign.Both countries can gain from trade, and will fully specialize in their comparative advantage.
8y2y2*L*/a2*B*pL/a2CC*A*ApapBpa*L/a1y1L*/a1*y1*Points B and B* represent the level of production of goods 1 and 2 in each country under specialization.C and C* are consumption in home and foreign.
9Comparative advantage and Wages (Feenstra pg. 4 note 2) Suppose Home has a comparative advantage in good 1.a1/a2 < a1*/a2*and an absolute disadvantage in both goods.a1 > a1*a2 > a2*In Free Trade suppose each country specializes (pa < p < pa*)-workers at home produce good 1 and earn w = p / a1-workers in foreign produce good 2 earn w* = 1 / a2*p = a1/a2 < a1*/a2*, rearranging: / a2* > p / a1*We assumed a1 > a1*, resulting in p / a1* > p / a1Wages in Foreign, w* = 1 / a2* > p / a1*> p / a1 = w
10Beyond 2 Goods, Dornbush, Fischer and Samuelson (1977) Generalization of Ricardian model to a continuum of goods, 𝑧∈[0,1] to allow integration.Again 2 countries, one factor of production, labor, in fixed supply (L and L*)Country-specific constant unit labor requirements: a (z) and a*(z)With relative home productivity which can be written as before:𝐴 𝑧 = 𝑎 ∗ 𝑧 𝑎 𝑧Assume that we can rank all goods so that A(z) is continuous and decreasing in z.price = marginal cost: P(z) = a(z)w and P*(z) = a*(z)w*Assume home production: P (z) < P*(z) or A(z) > w/w*
11Strong Structure on Demand Homothetic Demand: after winning the lottery I take my grocery list and double the purchases of every item.Constant expenditure Share b, demand C, total income YIdentical tastes across countriesMany products:𝑏 𝑖 = 𝑃 𝑖 𝐶 𝑖 /𝑌1 𝑛 𝑏 𝑖 =1Continuum of products:𝑏 𝑧 = 𝑃 𝑧 𝐶 𝑧 𝑌 >0b(z)=b*(z)0 1 𝑏 𝑧 𝑑𝑧=1Production at home:𝑣 𝑧 = 0 𝑧 𝑏 𝑧 𝑑𝑧
12Trade Equilibrium (DFS 1977) Domestic wages must equal world spending on domestic goods𝑤𝐿=𝑣( 𝑧 )(𝑤𝐿+ 𝑤 ∗ 𝐿 ∗ )Rewriting in terms of relative wages:w w ∗ = 𝑣 𝑧 1−𝑣 𝑧 L ∗ L =B 𝑧 ; L ∗ LCombine with the conditions for Home Production:𝐴 𝑧 = 𝑤 𝑤 ∗ =𝜔
14Hypothetical DFS Population Growth Suppose that the foreign country increases their population (possibly by integrating with another country).B(L*/L) is increasing in L*.Home will produce fewer goods, but wages rise. Home is better off, Real income risesWorkers in F lose, wages decline in terms of goods produced abroad.This is a Terms of Trade effect. The terms of trade are said to improve if the index of the price of a country's exports in terms of its imports rises.
16Criticisms of DFS/ Ricardian Model Does not generalize easily to more than two countriesComparative Advantage is generated by an exogenous technologyAssuming that costs are different across countries makes prediction difficult.Why wouldn’t technology spill across borders?
17The Heckscher-Ohlin (HO) Model The law of comparative advantage says that countries trade when autarky prices are different from free trade pricesAssuming persistent differences in technology seemed unprincipled.Variation in autarky prices can come from differences in factor endowments (capital, labor, skilled labor, land)Heckscher-Ohlin modelAt least two factorsFactors are stuck in countriesTechnology is identical in all countries
18H-O Two good, Two Factors (Labor and Capital) One Production Function (identical technology): 𝑦 𝑖 = 𝑓 𝑖 𝐿 𝑖 , 𝐾 𝑖 , 𝑖=1, 2 f is increasing, concave, and homogenous of degree 1 in L and K (Constant Returns to Scale) Resource Constraints: 𝐿 1 + 𝐿 2 ≤𝐿 𝐾 1 + 𝐾 2 ≤𝐾
19Duality: Unit Cost Functions Feenstra works with the dual of the production function:𝑐 𝑖 𝑤,𝑟 = min 𝐿 𝑖 ,𝐾 𝑖 𝑤 𝐿 𝑖 +𝑟 𝐾 𝑖 𝑓 𝑖 𝐿 𝑖 , 𝐾 𝑖 ≥1The solution of this function is written:𝑐 𝑖 𝑤,𝑟 =𝑤 𝑎 𝑖𝐿 𝑤,𝑟 +𝑟 𝑎 𝑖𝐾 𝑤,𝑟Note that using the envelope theorem (Shephard’s Lemma):𝜕 𝑐 𝑖 𝑤,𝑟 𝜕𝑤 = 𝑎 𝑖𝐿
20Equilibrium Conditions Zero Profit Conditions: Free entry in perfectly competition determines prices𝑝 1 = 𝑐 1 𝑤,𝑟 , 𝑝 2 = 𝑐 2 (𝑤,𝑟)Full employment Conditions: All resources are consumed: 𝐿 𝑖 = 𝑦 𝑖 𝑎 𝑖𝐿 and 𝐿 1 + 𝐿 2 =𝐿𝑎 1𝐿 𝑦 1 + 𝑎 2𝐿 𝑦 2 =𝐿, 𝑎 1𝐾 𝑦 1 + 𝑎 2𝐾 𝑦 2 =𝐾Notice that fixing prices, ZP determine w and r.The remaining equations determine 𝑎 𝑖𝐾 and 𝑎 𝑖𝐿 .In equilibrium sectoral output levels (𝑦 1 , 𝑦 2 ) will depend on K and L but not factor intensities.
21Factor-price Insensitivity (Feenstra Theorem 1) With two goods and two factors, factor prices are uniquely determined by goods prices, irrespective of factor endowments.
22Factor-price equalization (Feenstra Theorem 2) Assume free trade, no transport cost, two goods, two countries, two factors, identical technologies, no factor-intensity reversals, and both countries produce both goods.Then factor prices are equalized in both countries irrespective of factor endowments.
23Stolper Samuelson Theorem An increase in the price of a good will more than proportionally increase the returns to the factor intensively used in the production of that good.Trade raises the real reward of a country’s abundant factor and reduces the real reward of its scarce factor.Trade leads to a conflict of interest between the scarce and abundant inputs.Trade leads to factor price convergence (Ohlin emphasized the tendency towards factor price convergence, but not equalization).
24Mathematical Statement of the Stolper Samuelson Theorem Suppose that: 𝑎 𝐿 1 𝑎 𝐾 1 > 𝑎 𝐿 2 𝑎 𝐾 2 then 𝜕ln 𝑤 𝜕 ln 𝑝 1 >1 Proof: Take total derivative of 𝐶 𝑖 𝑤,𝑟 = 𝑝 𝑖 for i=1,2 with respect to 𝑝 1 : 𝑎 𝐿 1 𝑑𝑤+ 𝑎 𝐾 1 𝑑𝑟=𝑑 𝑝 1 𝑎 𝐿 2 𝑑𝑤+ 𝑎 𝐾 2 𝑑𝑟=0
27Many Goods Heckscher-Ohlin-Vanek Model (Feenstra chapter 2) M factors, world endowment vector 𝑽= ( 𝑉 1 ,…, 𝑉 𝑀 ), indexed by kC countries with endowments 𝑽 𝒊 = ( 𝑉 1 𝑖 , … , 𝑉 𝑁 𝑖 ), indexed by ifactors are immobile across countries, perfectly mobile within countriesN industries produced with CRS as before.𝐴= 𝑎 𝑗𝑘 ′ is the factor requirement of production. The transposition implies that columns are the industries, rows are the factors.
28Factor Content of Trade 𝑌 𝑖 is the vector of outputs in each industry for country i.𝐷 𝑖 is the vector of demands for goods in each country i.𝑇 𝑖 = 𝑌 𝑖 − 𝐷 𝑖 is the net exports of country i.Factor content of trade is 𝐹 𝑖 ≡𝐴 𝑇 𝑖𝐴 𝑌 𝑖 is the demand for factors in i, set equal to endowment 𝑉 𝑖 .𝐷 𝑖 is homothetic and identical across countries, and trade is balanced so must be the share of income times world demand.𝐷 𝑖 = 𝑝 ′ 𝑌 𝑖 𝑝 ′ 𝑌 𝑊 𝐷 𝑊World consumption equals world production:𝑝 ′ 𝑌 𝑖 𝑝 ′ 𝑌 𝑊 𝐴𝐷 𝑊 = 𝑝 ′ 𝑌 𝑖 𝑝 ′ 𝑌 𝑊 𝐴 𝑌 𝑊 = 𝑝 ′ 𝑌 𝑖 𝑝 ′ 𝑌 𝑊 𝑉 𝑊𝐹 𝑖 ≡𝐴 𝑇 𝑖 =𝐴 𝑌 𝑖 − 𝐷 𝑖 =𝐴 𝑌 𝑖 −𝐴 𝐷 𝑖 = 𝑉 𝑖 − 𝑝 ′ 𝑌 𝑖 𝑝 ′ 𝑌 𝑊 𝑉 𝑊
29Pattern Of Trade in Each Factor 𝐹 𝑘 𝑖 = 𝑉 𝑘 𝑗 − 𝑝’ 𝑌 𝑖 𝑝’ 𝑌 𝑊 𝑉 𝑘 𝑊 is the Heckscher-Ohlin-Vanek Theorem for each factor 𝑘.Comparative advantage in each factor k can be determined by the share of world endowment of factor k over the share of world GDP.If 𝑉 𝑘 𝑖 𝑉 𝑘 𝑊 > 𝑝 ′ 𝑌 𝑖 𝑝 ′ 𝑌 𝑊 then country 𝑖 is abundant in factor 𝑘.This implies that 𝐹 𝑘 𝑖 >0, or that the abundant factor is exported.
30The Leontief Paradox Using U.S. input-output tables from 1947: The capital labor ratio in U.S. exports was $13,700 of capital per man-yearThe capital labor ratio in U.S. imports was $18,200 of capital per man-yearThe U.S. is relatively capital abundant after WWII and should export capital intensive products and import labor intensive products.
31Leamer 1980 ObservationLeontief studied the factor content of exports and imports, but what matters is the relative factor abundance of production and consumption.𝐾 𝑖 − 𝐹 𝐾 𝐿 is the factor content of consumption of capital, while 𝐿 𝑖 − 𝐹 𝑙 𝑖 is the factor content of consumption of labor.For a capital abundant country𝐾 𝑖 𝐾 𝑖 − 𝐹 𝑘 𝑖 > 𝐿 𝑖 𝐿 𝑖 − 𝐹 𝑙 𝑖We would expect U.S. production to be more capital intensive than its consumption, which according to Feenstra Table 2.2, it is (slightly).
32Edgeworth Box of Factor content of Trade 𝑂 2𝑄 is employment in industry 1.Good 2𝑉 𝑖𝐹 𝑘 1𝐴𝐷 𝑖𝑲 𝑾 = 𝑲 𝟏 + 𝑲 𝟐𝐹 𝑘 2𝑄 1Good 1𝑂 1𝑳 𝑾 = 𝑳 𝟏 + 𝑳 𝟐
34Integrated Equilibrium: Imagine there are no countries Zero profit conditions𝑝 𝑖 = 𝑐 𝑖 𝒘 𝑖=1,…𝑁Factor markets clear𝑖∈𝑁 𝑎 𝑛𝑖 𝒘 𝑦 𝑖 = 𝑉 𝑗 𝑗=1,…𝑀Where 𝑦 𝑖 is the quantity of good i.Goods market clear𝑏 𝑖 𝐩 𝑗∈I 𝑝 𝑗 𝑥 𝑗 = 𝑝 𝑖 𝑥 𝑖 ∀𝑖∈𝐼Notice that the number of equations is equal to the number of unknown parameters.
35Return to Factor Price Equalization Goal is to replicate the equilibrium in the integrated equilibrium using trade in goods.Assume:every country uses the same input mix as in the integrated equilibrium.Full employment of factors in all countries.Because every country is using the same technologies, the factor prices will be the same. Because the factor prices are the same the goods prices p will be the same.Full employment and identical (p, w) imply the same income and production as the integrated equilibrium.