1. LECTURE 2: THE TRADE BALANCE
IN PRACTICE
Question: Is the Marshall-Lerner condition satisfied in practice?
1) Historical example:
Poland 2009
2) Econometric estimation of elasticities
OLS
The J-curve
3) Both determinants together: Real exchange rate & income
Keynesian model of the TB
Estimation for the case of East Asian countries

2. Historical example: Poland’s Exchange Rate Rose 35% when Global Financial Crisis hit in late 2008.
Zloty/€
Source: Cezary Wójcik

3. Poland’s trade balance improved sharply in 2009 while its European trading partners all went into recession.
Trade balance in billions of euros
Contribution of Net X in 2009: % of GDP > Total GDP growth: 1.7%
Source: National Bank of Poland From FocusEconomics 2014
=> Poland avoided recession.

4. % change in GDP (de facto)
A textbook case where depreciation was expansionary: Poland, the only continental EU member with a floating rate, was also the only one to escape negative growth in the global recession of 2009.
% change in GDP
(de facto)
Source: Cezary Wójcik, 2010

5. Empirical estimation of export & import elasticities
log of X demanded
log of EP*/P ≡ Price of foreign goods relative to domestic goods
Coefficient estimated by OLS regression.
In logs, so parameters are elasticities.

6. Common econometric finding
Estimated trade elasticities with respect to relative prices often ≈ 1, after a few years have been allowed to pass.
=> Marshall-Lerner condition holds in the medium run.
e.g., Marquez (2002).
Some face a higher elasticity of demand for their exports:
small countries, and
producers of agricultural & mineral commodities or other commodities that are close substitutes for competitors’ exports.

7. Common empirical observation: After a devaluation,
trade balance gets worse before it gets better.
Explanation:
Even if devaluation is instantly passed through to higher import prices,
buyers react with a lag.
Also, in practice, it may take time up front before the devaluation is passed through to import prices.
εX + εM > 1
εX + εM < 1
εX + εM > 1
εX + εM < 1

8. The trade balance is a function of both the real exchange rate and income.
Recall the Keynesian model of the trade balance from Lecture (iii) of the pre-semester Macro Review.
Micro theory: The demand for the import or export good, as for any good, is a function of both price & income.

9. Keynesian Model of the Trade Balance
Import demand is a function of the exchange rate & income. The same for exports: =>  X = X(E, Y*) M = M(E, Y)   .
If the domestic country is small, Y* is exogenous.

10. elasticities are mostly
Estimated price
elasticities (LR)
satisfy the
Marshall-Lerner
Condition.
Estimated income
elasticities are mostly
between

11. END OF LECTURE 2: THE TRADE BALANCE IN PRACTICE

12. An application of the marginal propensity to import
Appendix 1:
An application of the marginal propensity to import
Why did trade fall so much more sharply than income in the global recession?
Professor Jeffrey Frankel, Kennedy School, Harvard University

13. Why did trade fall so much more sharply than income
in the global recession?
2009
Bussière, Callegari, Ghironi, Sestieri, & N.Yamano, 2013, "Estimating Trade Elasticities: Demand Composition and the Trade Collapse of "

14. Why did trade fall so sharply in the 2008-09 global recession
Why did trade fall so sharply in the global recession?, continued
Bussière, Callegari, Ghironi, Sestieri, & Yamano, 2013, "Estimating Trade Elasticities: Demand Composition and the Trade Collapse of "
The usual explanations involve trade credit, inventories, and trade in intermediate inputs.

15. Behavior of real components of GDP in the 2008-09 recession
Bussière et al (2013) argue that Investment, which declined much more in 2009 than the other components of GDP, has a higher marginal propensity to import than the other components.
Behavior of real components of GDP in the recession
Consumption
GDP
Demand, adjusted for import-intensity
Imports & Exports
Investment
Bussière, Callegari, Ghironi, Sestieri, & N.Yamano, "Estimating Trade Elasticities: Demand Composition and the Trade Collapse of “

16. Trade growth continues to be slow, and slow investment continues to be a possible explanation.
IMF WEO, 2016 Apr., Fig. 1.13