IV: INTEGRATION OF GOODS MARKETS

Transcription

1 IV: INTEGRATION OF GOODS MARKETS LECTURE 11: EMPIRICAL TESTS OF PPP (PURCHASING POWER PARITY) Motivating questions: How integrated are goods markets internationally? How rapidly do prices adjust?

2 PPP: ALTERNATIVE DEFINTIONS Absolute PPP : P price of a basket of goods in domestic currency (e.g., from the Penn World Tables or the UN s International Comparison Program). RER = 1, where real exchange rate RER E P P = E P* P E = P P = 1/P 1/P In logs: e = p - p*.

3 Prof. Jeffrey Frankel, Harvard Kennedy School PPP: ALTERNATIVE DEFINTIONS (continued) Relative PPP CPI is a price index, expressed relative to an arbitrary base year e.g., CPI (from national agencies). Define real exchange rate Q E CPI CPI. Q is constant (at Q), CPI = 1 Q (E)(CPI*). In logs, Δe = Δ cpi Δ cpi* (relative to some base year). or Annual depreciation = π - π*. E = Q CPI CPI.

4 API120 - Prof. J.Frankel Does PPP hold: PPP: EMPIRICAL QUESTIONS In the short run? No. In the long run? Maybe. What is the estimated speed of adjustment to the LR? Are PPP deviations: related to variation in nominal exchange rates? - Can one infer causality? related to geography? - To distance? To borders? Does the Law of One Price hold better in some sectors than others?

5 PPP holds well in hyperinflations (a sort of long run): The cumulative change in E corresponds to the cumulative change in CPI. API120 - Prof. J.Frankel

6 API120 - Prof. J.Frankel PPP fails badly in the short run. Why? ΔE with sticky prices? So ΔE => ΔQ? Or does the same exogenous real ΔQ coming from productivity or terms-of-trade shocks show up as ΔE or ΔP, depending if on floating vs. fixed? Three useful kinds of evidence: (1) The pattern of movement in real exchange rates: band or threshold Random Walk trend AR. (2) Effects of exchange rate regime on variability in Q. (3) Tests of Law of One Price for narrowly defined goods.

7 API120 - Prof. J.Frankel (1) Four patterns of deviation from PPP and their likely origins: Q Q Q a) Band <= barriers to trade b) Random walk <= shifts in terms of trade c) Trend <= Balassa- Samuelson effect d) Autoregression <= sticky prices. Q Band Trend Q Q Random Walk Autoregression

8 Specification of PPP test as an AutoRegressive process q t = k + δ q t-1 + δ AR coefficient; (1-δ) speed of adjustment. H 0 : δ = 1 H 1 : δ = 0 H Alt : 0 < δ <1 u t where q log of real exchange rate; u t random disturbance with E(u t ) = 0. (random walk, or unit root) (full adjustment to PPP) (gradual adjustment to PPP). Common finding in tests of 1980s: can t reject H 0. True problem: Insufficient power in the tests, due to insufficient data. Since 1990, studies have sought more data. API120 - Prof. J.Frankel

9 q t With 100 or 200 years of data it is not hard to reject a random walk, i.e., to detect regression to the mean.

10 Studies with long time series: Time Period Estmt. δ Speed of Adjustment Half-life (years) JF (1990) Updated WTP (2007) (s.e.=.05) Lothian & M. Taylor (1996) 2 centuries 3-5 Alan Taylor (2002) 19 currencies (s.e.=.01) Papell & Prodan (2005) Cross-country panel data studies: Number of countries Frankel & Rose (1995) Wei & Parsley (1998) Choi, Mark & Sul (2004) API120 - Prof. J.Frankel

11 One lesson: reversion to LR Q Some have trends. Taylor spliced together 100+ years of data for 20 currencies: API120 - Prof. J.Frankel

12 (2) Var(e t ) and Var (q t ) are correlated across regimes. Is it coincidence? No, it can t be: Every time a regime switch raises variability of nominal exchange rates, it also raises variability of real exchange rates. Pre- and post-1973 (Fig. 19.4) Inter-war period (Eichengreen, 1988): float vs fix Post-war regimes (Mussa, 1986): Canadian float in the 1950s A century of PPP (A.Taylor, 2002): Gold standard Interwar Bretton Woods Float

13 Figure 19.4 Nominal & real exchange rates both became more volatile after Monthly Changes in Nominal Japanese Yen /Dollar Rate percent change When nominal exchange rate variability ( /$) went up with floating, real exchange rate variability went up in tandem. Monthly Changes in Real Japanese Yen /Dollar Rate percent change Coincidence? API120 - Prof. J.Frankel

14 The final nail in the coffin: Exchange rate variability across a century of regimes Each observation is a country-regime. (Adapted from A.Taylor, 2002) Variability of real exchange rate Again, each time a more flexible regime raises nominal variability, it raises real variability too. Variability of nominal exchange rate

15 (3) Tests of the Law of One Price (LoOP) 1. NonTraded Goods & Services, e.g., haircuts & housing have little scope for arbitrage. 2. Commodities oil, minerals, & agriculture. -- where arbitrage can potentially work very well. 3. Disaggregated manufactures 4. Retail: In reality, even TGs have a NTG component (distribution & marketing), & vice versa. McDonalds hamburgers. The Economist Parsley & Wei (2003). Some models make the TG/NTG line endogenous: Bergin (2003); Ghironi & Melitz (2004) 5. Pass-through of import prices. API-120, Prof.J.Frankel

16 1. NTGs Prices of nontraded services vary widely. Notice that they are lower in poorer (low-wage) countries than in high-wage countries. Professor Jeffrey Frankel,

17 2. Commodities Arbitrage equalizes prices for a homogenous metal such as gold => The Law of One Price holds. { Note: India has tariffs & quotas on gold imports. ITF-220 Prof.J.Frankel G.Alessandria & J.Kaboski, 2008, Why are Goods So Cheap in Some Countries? Business Review Q2 (Fed,Res,Bank of Philadelphia), Table 2.

18 Professor Jeffrey Frankel, Harvard University 3. Manufactures Giovannini, JIE, 1988 Even in a manufacturing sector as disaggregated and seemingly standardized as ball bearings, the relative price in Japan varies (1) widely, and (2) in correlation with the /$ exchange rate.

19 4. Big Macs Jan.22, 2014 Why was the price of Big Macs so high in Norway? Big Macs are partly traded (ingredients) & partly nontraded (cooking & retail). Their price varies widely across countries. higher in Brazil than in Japan? It tends to be higher in rich countries and in countries with overvalued currencies. Low in India & S.Africa? ITF-220 Prof.J.Frankel

20 5. Pass-through to import prices Import prices in Turkey show much more passthrough from depreciation than in the US. With standard error bands Gita Gopinath, 2015, The International Price System, NBER Working Paper, No , Oct. A 10% depreciation of the Turkish Lira results in its import prices in Lira rising by 9.3% one quarter after the shock and by 10.0% eight quarters after the shock [full pass-through]... In the case of the U.S. (thick dashed line) the numbers are much lower at 3.4% and 4.4%.

21 passthrough coefficient Pass-through coefficient % change in local price resulting from a given % change in exchange rate. Pass-through is greatest for imported goods at dock, but less for prices of the same goods at retail level. Reason: local distribution & retail costs. The pass-through to prices of local substitutes is again less; and is still less to the CPI. Exchange Rate Passthrough to Domestic Prices Exchange rate pass-through to domestic prices developing and other countries, at the dock imported good prices local competitor prices consumer price index Source: Frankel, Parsley & Wei (2012)

22 passthrough coefficient Passthrough coefficients for less developed countries > for rich, historically. Passthrough and Income (Average ) (Country Grouping Based on World Bank Classification) countries 36 countries countries Source: Frankel, Parsley & Wei (2012) 0 Low Income Middle Income High Income

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24 Looking ahead Barriers to International Integration -- Transportation costs -- Tariffs & non-tariff trade barriers -- Border frictions -- Currencies Non-Traded Goods -- The Balassa-Samuelson Effect