UDC: 336.748 JEL Classification: F31, F33, C32 Keywords: exchange rate – endogenous liquidity – error-correction mechanism – nonlinearity Liberalized Markets Have More Stable Exchange Rates: Short-Run Evidence from Four Transition Coutries
Ale‰ BULͤ*
1. Introduction This paper examines the hypothesis that financial market liberalization can create a basis for more stable exchange rates, as deviations of exchange rates from equilibrium levels, defined here as the Hodrick-Prescott filter, bring forth stabilizing flows of liquidity. This “endogenous liquidity” hy- pothesis is relevant in the context of the gradual switch from pegs to floats in Central European countries – both to the extent that pegs are more dif- ficult to maintain in liquid markets that respond quickly to participants’ changing perceptions and to the extent that such markets create more fa- vorable conditions for a market-determined exchange rate. Models of foreign exchange markets with endogenously provided liqui- dity assume that large deviations from longer-term pricing levels attract marginal liquidity into the market, which in turn speeds up the market’s return toward its trend-based value (Sarno, 2003). Hence, markets with a large number of informational traders or with deep order books ought to have smaller and shorter deviations of the exchange rate from trend. The fact that endogenous liquidity (the client order flow) can affect market exchange rates is well known, and Faruqee and Redding (1999), Evans and Lyons (2002), Bacchetta and van Wincoop (2003), and Derviz (2004) present theoretical models of endogenous liquidity and foreign exchange mi- crostructure that capture this impact. Empirically, the liquidity effect has been shown by Faruqee and Redding (1999) on a sample of G-7 currencies, and the order flow effect by Evans and Lyons (2002). We tested the endogenous liquidity hypothesis using daily and weekly ex- change rate data for the U.S. dollar and euro against the Czech and Slovak korunas, Hungarian forint, and Polish zloty for the relatively tranquil 1998–2002 period. First, we examined the statistical properties of the se- ries and found excess kurtosis present in the exchange rate returns. Se- cond, we identified transitory movements and trends in the data using
* International Monetary Fund ([email protected]) This work was undertaken while the author was on sabbatical leave at the Research De- partment of the Czech National Bank. The paper benefited from comments by Josef Arlt, Bergljot Barkbu, Alexis Derviz, Bob Flood, TomበHolub, Miroslav Hrnãífi, Kornélia Krajnyák, TomበKvapil, Tim Lane, Martin Mandel, Alex Mourmouras, Katefiina ·mídková, István Szekély, participants at the 55th IAEA conference, and seminar participants at the Prague University of Economics, Czech National Bank, and International Monetary Fund.
206 Finance a úvûr – Czech Journal of Economics and Finance, 55, 2005, ã. 5-6 the Hodrick-Prescott filter. While the filter sidesteps the problem of pro- longed misalignment, the medium-term exchange rate is what we observe in the data, it is not equivalent to the fundamental-based exchange rate. Finally, we tested the speed-of-adjustment hypothesis within an error-cor- rection framework, finding results comparable to those of Faruqee and Red- ding (1999). The results are broadly supportive of the endogenous liquidity hypothe- sis as the effects of endogenous liquidity are comparable to those of the ran- dom walk in exchange rate determination. The results also suggest that early foreign-exchange market and financial-account liberalization might explain the resulting faster-than-average adjustment of some national cur- rencies to short-term deviations from the trend, even if the trend itself may reflect prolonged misalignment. Liberalized and comparatively large mar- kets, such as the Czech Republic, are likely to be more stable than those that are smaller, such as the Slovak Republic, or less fully liberalized ones, such as Hungary in the late 1990s. Other results indicate that the speed of adjustment of national exchange rates is typically faster vis-a`-vis the euro as opposed to the dollar, an intu- itive consequence of the region’s link to the euro area. These results also seem to be in line with the finding that volatility of exchange rates in the re- gion appears to be only loosely related to the national exchange rate ar- rangements (Darvas – Szapáry, 2000), (Wickham, 2002), or (Canales-Kril- jenko – Habermeier, 2004). In addition, our results imply that central banks should not be overly concerned with short-run volatility of their national exchange rates, given the self-correcting tendencies. The paper is organized as follows. After discussing the model and sty- lized facts, we examine the data properties and outline the empirical tech- niques. In the following section we present our results. The final section concludes.
2. A Model of Short-term Exchange Rate Determination
Macroeconomists have long observed that exchange rates – both in no- minal and real terms – are more volatile than would seem to be justified by conventional macroeconomic models and that the models’ short-term ex- planatory power is limited (Meese – Rogoff, 1983). Clearly, exchange rates can remain fairly long outside of the “fair” value, be it based on funda- mental- or equilibrium-based calculations. In contrast, models augmented with microeconomic variables – such as the order flow of foreign exchange in the field of microstructure finance – seem to do much better in the short term.1
1 Order flow is defined as the net of buyer-initiated and seller-initiated orders. In conventional macroeconomic models actual trades are typically not related to exchange rate movements. Em- pirical examples of the link between order flow and daily exchange rate returns were docu- mented for the U.S. dollar/deutsche mark and Czech koruna/euro rates by Evans and Lyons (2002) and Derviz (2004), respectively. Unfortunately, the existing order flow data have been collected in an ad hoc fashion and are yet to be tested in a long-run sample. For example, the Evans and Lyons paper uses a four-month period in 1996 and Derviz’s data run from mid- -1999 until end-2001.
Finance a úvûr – Czech Journal of Economics and Finance, 55, 2005, ã. 5-6 207 2.1 Foreign Exchange Markets in the Short Run
In reality, foreign exchange flows and exchange rates are linked endoge- nously. Only a fraction of foreign exchange trading is related to a desire to take a particular asset position, for the purposes of either financial invest- ment or foreign trade activity, and the remainder is initiated by some traders providing liquidity to other traders for an expected profit. The expected profit may be based on a sudden departure from a longer-term level of the ex- change rate or an increase in the bid-ask spread. Intuitively, large and sud- den deviations from the longer-term level of the exchange rate would either activate limit orders set by the existing traders or attract new traders into the market, accelerating the exchange rate’s return back to its longer-term level. While this may be a typical reaction to most deviations from the trend, it could be attenuated by foreign exchange trading based on chartist or tech- nical analysis techniques. Market participants are likely to place large limit orders only in deep and transparent markets. Taking a clue from the theory of finance: “investors tend to invest in instruments they are aware of” (Merton, 1987). On the one hand, knowing that the market for a given currency is deep, as for exam- ple where there is a large volume of limit orders on exchange rate move- ment in either direction away from trend, agents would presumably be less prone to initiate sharp price adjustment to nonfundamental news. On the other hand, the return to longer-term equilibrium values ought to be faster with a deep market, because those limit orders would be activated or new market makers would enter such a market quickly to take advantage of the profit opportunity.2 In reality, the former effect is likely to dominate the latter: the number of foreign exchange dealers in transition countries has been low and stable in the short run. Controlling for exchange rate regimes, foreign exchange market history, central banks’interventions, both open and hidden, and so on, deep markets ought to exhibit faster adjust- ment to longer-term levels of exchange rates. In contrast, central bank interventions should not have a significant smoothing impact on the foreign exchange market. Contrary to the con- ventional view of interventions as an instrument of stabilizing short-term fluctuations, Central European central banks were mostly “leaning against the wind”, trying to slow down real exchange rate appreciation. We discuss the evidence in favor of this view later in the paper.
2.2 An Outline of a Theoretical Model
How would an economy with endogenous liquidity operate? Faruqee and Redding (1999, 2001) and Evans and Lyons (2002) employed three-period, short-term models that share some salient features and we will use a sim- plified version thereof to motivate the empirical work in our paper. Arguably,
2 The empirical literature provides some support for this hypothesis. For example, Devereux and Lane (2003) found that high levels of financial linkages between creditor and developing countries resulted in a lower level of bilateral exchange rate variability.
208 Finance a úvûr – Czech Journal of Economics and Finance, 55, 2005, ã. 5-6 FIGURE 1 Time Line of Exchange Rate Determination
Period 1 (T1)Period 2 (T2)Period 3 (T3)
First-period The net 1EP3 is Public Second-period 2EP3 is Public The market is informational demand revealed trading informational revealed trading liquidated at
traders enter of “noise” results traders enter results a price P3 the market and traders in a rate the market and in a rate
limit orders are is an- P1 limit orders are P2 set nounced set the Evans and Lyons model is geared toward explaining intra-day move- ments in the exchange rate, while Faruqee and Redding are concerned with somewhat longer periods. However, the adjustment in both models is ef- fected through similar processes. Consider a three-period economy in which trading influences the price of foreign currency (the model is derived formally in Annex I). Ignoring dif- ferences between the direct and brokered markets, the economy is popu- lated by two types of agents. First, noninformational (“noise”) traders who trade primarily for purposes of financial investment or foreign trade acti- vity and may push the exchange rate away from the best estimate of the li- quidation price in each period. These traders do not have a longer-term view of the exchange rate and typically buy foreign exchange at a given price. Second, informational traders (or market makers), who provide desired li- quidity in exchange for an expected profit to be realized in period 3 when the market is liquidated. These traders speculate, with a view of returning the rate to a market clearing level.3
The asset will have a liquidation price (P3) in the final period that is not known with certainty prior to T3. The asset is being traded in the first two periods, T1 and T2, resulting in prices P1 and P2, gradually improving the pre- cision of the estimate of P3, i.e., 1EP3 and 2EP3. The first- and second-period estimates of P3 are normally distributed around P3 with posterior sample 2 2 2 2 variances of 1 and 2, respectively, such that 1 2. Naturally, if nonin- formational traders’ orders were completely absent, the second-period price would be equal to the expectation of the third-period price. The resulting time line of exchange rate determination is described in Figure 1. 2 2 The model assumption of gradual price discovery ( 1 2) implies that the expected exchange rate will drift toward its longer-term value. How- ever, the speed of adjustment is endogenous: the bigger the absolute value of the discrepancy between the expected final and realized first-period ex- change rates 1EP3 – P1 , the deeper the order book will be in the second period and the faster the reversion to P3.
2.3 An Error-correction Framework
The principal implication of the Faruqee-Redding model is that the speed of adjustment of exchange rates toward their longer-term values is propor-
3 Which particular instruments are used by individual market participants is a side issue, de- pending primarily on the structure of individual markets.
Finance a úvûr – Czech Journal of Economics and Finance, 55, 2005, ã. 5-6 209 tionately higher when the deviation from the trend level is large and the or- der book is deep. While the former hypothesis is directly testable, the lat- ter is not, given the absence of long-run order flow data. The empirical testing of exchange rate developments consists of two parts. First, defining e as the log of the exchange rate, we separate its longer-term trend level (f), which is presumably affected by fundamental factors, from the effects of transitory demand (n): e=f+n (1)
The decomposition was done using univariate techniques, namely the Ho- drick-Prescott filter.4 The filter was used to characterize the trend portion of the exchange rate, and the difference from the actual exchange rate was used to characterize the transitory demand. The pros and cons of using the above univariate techniques are obvious. First, we avoid the troublesome joint testing of the endogenous liquidity hy- pothesis and an ad hoc chosen model of long-term exchange rate determi- nation as in (Meese – Rogoff, 1983). Second, the Hodrick-Prescott filter sidesteps the problem of prolonged misalignment – the medium-term ex- change rate is what we observe in the data. The flip side is, of course, that filtering away short-term fluctuations is not equivalent to the fundamen- tal-based exchange rate. It is noteworthy that the literature offers very lit- tle agreement on what is the correct method of computing equilibrium ex- change rates, see the survey in (Bulífi – ·mídková, 2005). Moreover, filtering does not shed light on the nature of the trend process: the underlying trend can be stochastic, supporting an I(1) variable, or deterministic with broken trend and supporting an I(0) variable. Applying the selected filters we im- pose a fixed speed of adjustment of the trend to actual developments in all periods and all countries.5 On balance, however, we see the disadvantages of joint testing as more serious than those of mechanical filtering. Second, we explore the nature of the short-term fluctuations. The model predicts that the transitory departure from the trend ought to be short-lived and the exchange rate would revert in expectation to the trend value of the exchange rate (Annex I):