Inference and prediction in a multiple-structural-break model

This paper develops a new Bayesian approach to structural break modeling. The focuses of the approach are the modeling of in-sample structural breaks and forecasting time series allowing out-of-sample breaks. The model has several desirable features. First, the number of regimes is not fixed but is treated as a random variable. Second, the model adopts a hierarchical prior for regime coefficients, which allows for the coefficients of one regime to contain information about coefficients of other regimes. Third, the regime coefficients can be integrated analytically in the posterior density; as a consequence the posterior simulator is fast and reliable. An application to US real GDP quarterly growth rates links groups of regimes to specific historical periods and provides forecasts of future growth rates.     

Analysis of asymmetric response of exchange rate to interest rate differentials: The case of African Big 4

Using the case of four leading African economies, namely Algeria, Egypt, Nigeria and South Africa, this paper explores the possibility of asymmetric relationship between exchange rate and interest rate differential. In addition, it also tests whether accounting for structural breaks matters for the nexus. The results vary for the four countries based on the choice of exchange rate regime and countries involved in full-fledged floating or managed floating seem to respond more to variations in interest rate differential. Also, accounting for both asymmetries and structural breaks should not be disregarded when modelling this nexus.     

Structural breaks and GARCH models of exchange rate volatility

We investigate the empirical relevance of structural breaks for GARCH models of exchange rate volatility using both in‐sample and out‐of‐sample tests. We find significant evidence of structural breaks in the unconditional variance of seven of eight US dollar exchange rate return series over the 1980–2005 period—implying unstable GARCH processes for these exchange rates—and GARCH(1,1) parameter estimates often vary substantially across the subsamples defined by the structural breaks. We also find that it almost always pays to allow for structural breaks when forecasting exchange rate return volatility in real time. Combining forecasts from different models that accommodate structural breaks in volatility in various ways appears to offer a reliable method for improving volatility forecast accuracy given the uncertainty surrounding the timing and size of the structural breaks. Copyright © 2008 John Wiley & Sons, Ltd.     

An efficient Bayesian approach to multiple structural change in multivariate time series

This paper provides a feasible approach to estimation and forecasting of multiple structural breaks for vector autoregressions and other multivariate models. Owing to conjugate prior assumptions we obtain a very efficient sampler for the regime allocation variable. A new hierarchical prior is introduced to allow for learning over different structural breaks. The model is extended to independent breaks in regression coefficients and the volatility parameters. Two empirical applications show the improvements the model has over benchmarks. In a macro application with seven variables we empirically demonstrate the benefits from moving from a multivariate structural break model to a set of univariate structural break models to account for heterogeneous break patterns across data series.     

The Contribution of Structural Break Models to Forecasting Macroeconomic Series

This paper compares the forecasting performance of models that have been proposed for forecasting in the presence of structural breaks. They differ in their treatment of the break process, the model applied in each regime and the out‐of‐sample probability of a break. In an extensive empirical evaluation, we demonstrate the presence of breaks and their importance for forecasting. We find no single model that consistently works best in the presence of breaks. In many cases, the formal modeling of the break process is important in achieving a good forecast performance. However, there are also many cases where rolling window forecasts perform well. Copyright © 2014 John Wiley & Sons, Ltd.     

Unemployment in Greece: Evidence from Greek regions using panel unit root tests

The purpose of the paper is to examine the nature of Greek regional unemployment. The paper contributes to the literature assessing the stochastic properties of Greek unemployment rate in the context of the Greek regions by relying on various univariate and panel unit root tests. In particular, recently developed and more powerful panel unit-root tests that control for structural breaks, heterogeneity and cross-sectional dependence in the panel are employed. The results show that in all cases, after taking into account the fact that regional unemployment rates in Greece are subject to a structural break, the null hypothesis of a unit root is not rejected, indicating that the Greek regional unemployment series are non-stationary with the presence of a structural break.     

“Global factors,international spillovers,and the term structure of interest rates: New evidence for Asian Countries”

This paper provides new evidence about the role of common global factors exploring the existence of structural breaks in the long-run trend of the term structure and analyzes the spillover effects from the unconventional monetary policies recently implemented by major industrialized countries. For a panel of four Asian economies (Malaysia, Philippines, Singapore, South Korea), we show that, accounting for the role of global liquidity factors, parameters restrictions associated with the EHTS are not rejected, even after a regime-shift occurring at the end of 2005, thus supporting an extended weak version of the “Liquidity Premium Theory”. We also document relevant discrepancies in the short-run dynamics of long-term interest rates, which are strictly related to some structural differences between these Asian countries in terms of the “impossible trinity” between monetary independence, financial openness and exchange rate stability.     

Inclusion of the RMB in SDRs and the impossible trinity in China

This paper explores the dynamics and features of the impossible trinity configuration in China, in the process of reforming the renminbi (RMB) exchange rate and inclusion in the currency basket of special drawing rights (SDR). By applying the synthetic model of Ito and Kawai (2014) and Aizenman et al. (2008) to Chinese data for the period between 2002 and 2019, we find structural breaks in China’s exchange rate stability in 2005, when China started its market-oriented exchange rate reform, and 2016, when the RMB was included in the SDR. More importantly, we find that, in the process of RMB exchange rate reform and RMB’s inclusion in the SDR, China has adopted a more flexible exchange rate regime, becoming more financially open, monetarily independent, and less reliant on international reserves hoarding.     

Common breaks in means and variances for panel data

This paper establishes the consistency of the estimated common break point in panel data. Consistency is obtainable even when a regime contains a single observation, making it possible to quickly identify the onset of a new regime. We also propose a new framework for developing the limiting distribution for the estimated break point, and show how to construct confidence intervals. The least squares method is used for estimating breaks in means and the quasi-maximum likelihood (QML) method is used to estimate breaks in means and in variances. QML is shown to be more efficient than the least squares even if there is no change in the variances.     

Exchange rates in the new EU accession countries: What have we learned from the forerunners?

Estimation and simulation of sustainable real exchange rates in some of the new EU accession countries point to potential difficulties in sustaining the ERM2 regime if entered too soon and with weak policies. According to the estimates, the Czech, Hungarian, and Polish currencies were overvalued in 2003. Simulations, conditional on large-model macroeconomic projections, suggest that under current policies those currencies would be unlikely to stay within the ERM2 stability corridor during 2004–2010. In-sample simulations for Greece, Portugal, and Spain indicate both a much smaller misalignment of national currencies prior to ERM2, and a more stable path of real exchange rates over the medium term than can be expected for the new accession countries.     

The effects of external and internal shocks on total factor productivity

This paper examines structural changes that occur in the total factor productivity (TFP) within countries. It is possible that some episodes of high economic growth or economic decline are associated with permanent productivity shocks; therefore, this research has two objectives. The first one is to estimate the structural changes present in TFP for a sample of 77 countries between 1950 (1960) and 2000. The second one is to identify possible explanations for breaks. Two sources were analyzed: (i) episodes in political and economic history; (ii) changes in international trade – a measure of absorption of technology. The results suggest that about one-third of the TFP time-series present at least one structural break. Downwards breaks are more common, indicating that after a break the TFP has much difficulty to recover. When we investigated factors related with structural change, developed countries presented a break near the first oil shock while the developing countries’ breaks are more spread along the decades. Thus, external strikes seem to be more relevant for developed countries. However, for each country and break date, it was possible to find an event close to the break date endogenously detected. Last, the relevance of international trade, measured by trade share percentage of GDP, seems to be limited to explain abrupt changes in TFP.     

Testing for structural breaks in dynamic factor models

In this paper we investigate the consequences of structural breaks in the factor loadings for the specification and estimation of factor models based on principal components and suggest procedures for testing for structural breaks. It is shown that structural breaks severely inflate the number of factors identified by the usual information criteria. The hypothesis of a structural break is tested by using LR, LM and Wald statistics. The LM test (which performs best in our Monte Carlo simulations) is generalized to test for structural breaks in factor models where the break date is unknown and the common factors and idiosyncratic components are serially correlated. The proposed test procedures are applied to datasets from the US and the euro area.     

我国的汇率制度弹性、资本流动性与货币政策自主性研究

本文实证研究了2005年7月21日汇率制度改革前后我国的汇率制度弹性、资本流动性和货币政策自主性的系统变化情况。研究结果表明,汇改后我国汇率制度弹性增强,资本流动性减弱,同时利率政策自主性增强,但货币数量政策则由汇改前的具有自主性变为缺乏自主性;在我国通过增强汇率制度弹性以提高利率政策自主性是可行的,但对货币数量政策并不成立。研究结果同时也表明,我国应以利率为货币政策中介目标。     

Is There a Natural Rate of Crime?

Studies in the economics of crime literature have reached mixed conclusions on the deterrence hypothesis. One explanation that has been offered for the failure to find evidence of a deterrent effect in the long run is the natural rate of crime. This article applies univariate unit root tests to crime series for the United Kingdom and United States and panel unit roots to crime rates for a panel of G7 countries to examine whether there is a natural rate of crime. Our main finding is that when we allow for two structural breaks in the univariate unit root test and a structural break in the panel data unit root test, there is strong evidence of a natural rate of crime. The policy implications of our findings is that governments should focus on altering the economic and social structural profile that determines crime in the long run rather than increasing expenditure on law enforcement that will at best reduce crime rates in the short run.     

Monetary Targets and the World Economy: A Progress Report

The recent changes in the value of the dollar and the talk of an interest rate ‘war’ demonstrate again that the world finds it difficult to cope with rapid exchange rate movements. In some ways the experience - and the reactions to it - are similar to the events of 1978. As now, the world was in a recession (though on a milder scale) and there were fears that exchange rate problems would obstruct economic recovery. The main difference is that in 1978 it was the strength of the Deutschmark which caused concern whereas this time the problems are associated with the rise in the value of the dollar. In a Briefing Paper in Economic Outlook, February 1978, ‘Monetary Targets and the World Economy’ we suggested that the problem arose from inconsistencies between national monetary policies and exchange rate objectives. In general, countries dislike exchange rate changes - in either direction - and there were problems because countries would not accept the exchange rate consequences of their own or other countries' monetary policies. We estimated the required monetary policies for stable exchange rates and suggested specific national monetary targets for 1978 which would at least move the world economy towards consistent monetary policies. In this Economic Viewpoint we return to those ideas. We consider what happened in 1978 and we also revise the underlying monetary rules. More recent experience suggests that although there has been some progress towards the convergence of monetary policies there will continue to be trend changes in exchange rates. It is also clear that there will be short-term fluctuations around these trends. We believe that greater convergence of monetary policies would be desirable but failing that it is important that countries should avoid abrupt changes in monetary policy. It is also important that countries should become accustomed to exchange rate changes. They should direct monetary policy towards their objectives for inflation and should not be diverted from it by temporary or permanent changes in their exchange rates.     

Structural break tests and the Greek sovereign debt crisis: revisited

Amidst the lack of consensus from previous academic studies, this paper contributes to existing literature by further examining the commencement date of the Sovereign Debt Crisis for the Greek economy. The contribution of this paper purports that the contentious issue of the start of the Greek crisis was taking place much earlier than reported by previous research. Empirical results from this paper challenge earlier studies that may have underestimated the impact of the degree of persistence in the volatility of bond returns. This analysis uses monthly 10-year Greek government bond data and three independent structural break model tests which allow for the detection of possible endogenous break dates to capture the beginning of the crisis. Each model provides empirically plausible and robust frameworks for examining the volatility of bond returns in an evolving time series behaviour. Ultimate results from a series of autoregressive EGARCH estimations, with and without dummy variables for break dates are compared. The dummy variables are incorporated within the coefficients of the mean and variance equations to validate the structural breaks in each series. Overall results show a significant presence of nonconsistent parameters capturing a structural break in the time series sample. The detection of this break, November 2009, represents a major regime change triggered by the start of the debt crisis for the Greek economy. Crucially, research implications of such excess volatilities in sovereign bond markets have poignant implications for regulators, investors and portfolio risk managers alike.     

The impact of offshore exchange rate expectations on onshore exchange rates: The case of Chinese RMB

This paper examines the impact of offshore RMB exchange rate expectations on onshore RMB (CNY) exchange rates. Employing data for the period of 2005–2018, we show that overall offshore market expectations influence onshore RMB rates, but this effect is significant only for the period after the “Second exchange rate regime reform” in 2010. The non-uniform nature of this impact is also confirmed by the existence of a threshold effect of the expectations in the same period. The study improves our understanding of how the offshore RMB market influences onshore RMB spot rates as a result of the marketization reform of the RMB exchange rate regime.     

Partial Structural Break Identification

We propose an extension of the existing information criterion‐based structural break identification approaches. The extended approach helps identify both pure structural change (break) and partial structural change (break). A pure structural change refers to the case when breaks occur simultaneously in all parameters of regression equation, whereas a partial structural change happens when breaks occur in some parameters only. Our approach consistently outperforms other well‐known approaches. We also extend the simulation studies of Bai and Perron ( 2006 and Hall, Osborn and Sakkas ( 2013 ) by including more general cases. This provides more comprehensive results and reveals the cases where the existing identification approaches lose power, which should be kept in mind when applying them.     

Which exchange rate regimes in an era of high capital mobility?☆

This paper asks what influence increasing capital mobility has on the choice of exchange rate regime. Among exchange rate regimes considered are currency boards and dollarization. It is argued that a key lesson of the recent currency and financial crises in the emerging markets is that corner solutions in exchange rate policy may be preferable to less rigidly fixed exchange rates. The paper concludes that in the end the optimal exchange rate regime depends on the circumstances of a particular country and time, because each exchange rate system requires the fulfillment of certain preconditions. The paper then discusses institutional measures and innovations that may be necessary to enable exchange rate arrangements to avoid financial and currency crises or to dampen their consequences.     

Forecasting a long memory process subject to structural breaks

We develop an easy-to-implement method for forecasting a stationary autoregressive fractionally integrated moving average (ARFIMA) process subject to structural breaks with unknown break dates. We show that an ARFIMA process subject to a mean shift and a change in the long memory parameter can be well approximated by an autoregressive (AR) model and suggest using an information criterion (AIC or Mallows’ _Cp$C_p$) to choose the order of the approximate AR model. Our method avoids the issue of estimation inaccuracy of the long memory parameter and the issue of spurious breaks in finite sample. Insights from our theoretical analysis are confirmed by Monte Carlo experiments, through which we also find that our method provides a substantial improvement over existing prediction methods. An empirical application to the realized volatility of three exchange rates illustrates the usefulness of our forecasting procedure. The empirical success of the HAR-RV model can be explained, from an econometric perspective, by our theoretical and simulation results.