An algorithmic approach to exchange rate stabilization

Exchange Rate Dynamics in a Target Zone - A Heterogeneous Expectations Approach

This article presents a new way of modeling the dynamics of an exchange rate target zone. In the presence of a single upper (lower) target boundary, the exchange rate is precisely represented as the sum of a free float and a short (long) position in a call (put) option with strike price at the boundary. To model a target zone (with two boundaries), a natural approach consists of describing the exchange rate dynamics as the combination of the two, namely the sum of free float together with a long position in a put written on the lower boundary and a short position in a call option written on the upper boundary, respectively. The authors show that this first order approximation leads to significant mispricing (as much as 20%) and must be iterated, leading to an infinite sequence of compounded “mirrored” option prices. They analyze basic properties of such mirrored nested options analytically, describe how to calculate them numerically, and show why it is crucial to take into account higher order corrections in realistic target zones. They argue that this analogy to option prices allows for conceptually simple generalizations that describe different target zone arrangements. They then apply their methodology to the estimation of the fundamental value of the Hong Kong dollar that is hidden by the target zone pegged to the US dollar. They also estimate the implied maturity and explain how this parameter serves as direct proxy for target zone credibility.

Exchange rate and central bank intervention is an important topic in the exchange rate determination [1-4]. Exchange rates are volatile after the breakdown of the Bretton Woods system of fixed exchange rate in the year 1973. Central banks especially those in economies adopted a managed exchange rate regime actively intervene in the exchange rate market to maintain their exchange rates and to reduce their exchange rate volatility, which can affect international trade, financial flow and economic growth. Central bank intervention in the exchange rate market may want to accrue international reserves to enhance the fundamental of the economy [5]. There are two important issues related to the exchange rate intervention, namely the effectiveness of central bank intervention and the success of central bank in maintaining the exchange rate and in reducing exchange rate volatility [1,4,6]. In general, the literature of exchange rate and central bank intervention is inconclusive on the impact of central bank intervention. Most studies conclude that central bank intervention tends to increase exchange rate volatility.

This paper analyzes credibility in the Colombian exchange rate target zone. A model of imperfect credibility, in the spirit of Bertola and Svensson (1993) is derived, and is used to explain why the exchange rate in Colombia has remained for prolonged periods near the borders of the zone. The main feature of the model is that central parity depreciation expectations are endogenous with respect to the position of the exchange rate inside the target zone. The krugman(1991) perfectly credible setup turns out to be a particular case of this general model. One of the main implications of the model is that depreciation expectations increase rather than decrease as the exchange rate approaches the upper band. Hence a model as the one presented in this paper, is useful to explain the recent dynamics of interest rates in Colombia. It is also shown, that this model shares empirical features with the basic target zone model. Hence, policy makers might be misled when trying to recognize their credibility stance. A estructural estimation of the underlying parameters of the model, using McFadden's (1989) method of simulated moments, is suggested to identify the presence of non credibility issues. Econometric evidence suggest that Colombia's exchange rate target zone is properly described by a model of this nature.

I examine authorities' interventions in goods and money markets to keep exchange rates within targeted zones, in an economy where both the exchange rate and the prices of goods are interdependent forward-looking variables. I show that, (1) in order to support target zones in both goods and money markets, there needs to be coordinated, simultaneous intervention in the two markets; (2) intervention takes place almost certainly before the exchange rate or the price level reaches its upper or lower bounds; and (3) zones for the exchange rate and for the price level cannot be separately designed as independent policy goals.

The first known experiment with an exchange rate band took place in Austria- Hungary between 1896 and 1914. The rationale for introducing this policy rested on precisely those intuitions that the modern literature has emphasized: the band was designed to secure both exchange rate stability and monetary policy autonomy. However, unlike more recent experiences, such as the ERM, this policy was not undermined by credibility problems. The episode provides an ideal testing ground for some important ideas in modern macroeconomics: specifically, can formal rules, when faithfully adhered to, provide policy makers with some advantages such as short term autonomy? First, we find that a credible band has a "microeconomic" influence on exchange rate stability. By reducing uncertainty, a credible fluctuation band improves the quality of expectations, a channel that has been neglected in the modern literature. Second, we show that the standard test of the basic target zone model is flawed and develop an alternative methodology. We believe that these findings shed a new light on the economics of exchange rate bands.

Part 1 International policy co-ordination and exchange rate management: the European monetary system, exchange rate expectations and the reputation of authorities, P.Artus would US protectionism be a threat to economic stability?, A.J.Hughes Hallett and G.J.Huston international adjustment and the dollar - a game theoretic approach, J.C.Martinez Oliva exchange rates and policy co-ordination in an asymmetric model, P.Kennen international policy co-ordination, imperfect information and target zones, A.Bisin and P.Tedeschi target zones, currency options and the dollar, P.Weller. Part 2 Strategic aspects of international policy co-ordination: time inconsistency, discounting and the returns to co-operation, M.Miller, et al policy co-operation among benevolent governments may be undesirable - an extension, P.J.Kehoe can international policy co-ordination really be counterproductive?, C.Carraro and F.Giavazzi profit shifting motives and international trade union co-ordination, D.Laussel and A.Soubeyran. Part 3 Information and uncertainty: robust lyapunov games under bounded uncertainty, C.Diessenberg asymmetric information and policy co-ordination, M.Cripps international policy co-ordination in a world with model uncertainty, A.R.Ghosh and P.R.Masson.

Monetary authorities of many open economies have been regularly intervening in foreign exchange markets for years to limit volatility in exchange rates and/or push exchange rates back to some desired level. Such interventions have taken the form of actual and oral official interventions. Review of studies investigating the effectiveness of interventions reveals one major issue, related to the assumption that interventions are mostly sterilized. This assumption might lead to unreliable results when changes in interest rates and interventions are both used as explanatory variables for exchange rates. One major consistent finding is that intervention has a significant but short-lasting effect on exchange rates. Studies have reached this conclusion by investigating whether intervention has been effective in turning around the exchange rate over the few days, weeks or months following intervention(s). Only a few studies have investigated and provided evidence that intervention has been effective in limiting long swings in exchange rates. Studies testing for the effectiveness of interventions specifically through the signaling channel also provide evidence on the importance of macroeconomic variables for exchange rates. The significance of official intervention and official communication for exchange rate movements combined with the importance of macroeconomic variables for exchange rates provide a role for official intervention and parity announcement to influence exchange rate movements and limit the magnitude of exchange rate swings.

A majority of countries neither freely float their currencies nor firmly peg. But most of the remainder in practice also don’t obey such well-defined intermediate exchange rate regimes as target zones. This paper proposes to define an intermediate regime, to be called “systematic managed floating,” as an arrangement where the central bank regularly responds to changes in total exchange market pressure by allowing some fraction to be reflected as a change in the exchange rate and the remaining fraction to be absorbed as a change in foreign exchange reserves. An operational criterion for judging systematic managed floaters is a high correlation between exchange rate changes and reserve changes. The paper rejects the view that exchange rate regimes make no difference. In regressions to test effects on real exchange rates, we find that positive external shocks tend to cause real appreciation for most systematic managed-floaters; more strongly so for pure floaters; and not at all for most firm peggers. Two measures of exogenous external shocks are used: (i) for commodity-exporters, a country-specific index of global prices of the export commodities and (ii) for other Asian emerging market economies, the VIX.

On the mean-reverting properties of target zone exchange rates: Some evidence from the ERM

‘Dog Days’ Full Employment without Depreciation: Can It Be Done?

The discussion of target zones for flexible exchange rates is evidence of the desire to experiment with new instruments for stabilising the international monetary system. What distinguishes target zones from systems of flexible and fixed exchange rates? What form should they take? How should one regard the various objections to target zones?

Daily Effects of Foreign Exchange Intervention: Evidence from Official Bank of Canada Data

External shocks and exchange rate regimes in Southeast Asia: A DSGE analysis

The paper aims to highlight the main difficulties on the monetary path towards the euro zone experienced by Emerging Europe. Emerging European Economies (EEEs), EU members, adopted either double shift or smooth transition monetary approach towards the euro zone. Double shift assumes changes from floating exchange rate regimes (ERRs) to the ERM II target zone and, finally, monetary union as a rigid ERR. The smooth transition is practiced by economies with mainly rigid ERRs before the ERM II entrance and, at the end, again rigid ERR of a monetary union. Despite chosen monetary path towards the euro zone, crucial difficulties or aggravating factors could be identified in the form of real exchange rate appreciation due to productivity growth or capital inflows. A reconciliation of inflation and exchange rate target zone is extremely complex, at the same time striving not to jeopardize the real convergence. What is stressed here is the vicious cycle between real and nominal convergence as the reason why the ERM II target should be regarded as a “waiting room“ not as a “training room“ in the pre-EMU phase.