Nonlinear adjustment to the mean reversion of consumption–income ratio

This study utilizes a flexible Fourier stationary test, proposed by Becker et al. (2006) to investigate the mean reversion of consumption–income ratio in 16 OECD countries from 1960 to 2010. Empirical results from our flexible nonlinear stationary test show that the mean reversion hypothesis is not rejected for 12 of the 16 OECD countries.     

Hysteresis in unemployment for 17 OECD countries: Stationary test with a Fourier function

In this empirical study, we apply stationary test with a Fourier function proposed by Becker et al. (2006) to re-examine the hysteresis hypothesis in unemployment for 17 OECD countries over the 1960 to 2009 period. The hysteresis in unemployment is confirmed for most of these 17 OECD countries, with the exception of Australia, Canada, Finland, France, Sweden and the USA, when Becker et al.'s (2006) stationary test with a Fourier function is conducted.     

Nonlinearity and stationarity of inflation rates: evidence from the euro-zone countries

Earlier studies hardly reject the hypothesis of a unit root in inflation. Few studies have examined the possibility of nonlinearity in inflation and tested nonlinear stationarity of the inflation rates. This study thus intends to fill the gap. This study utilizes the tests for nonlinearity along with the unit root tests that allow for nonlinearity in the variables to examine the stationarity of inflation rates of 12 European countries that formed the Euro Zone (EZ) later in the sample period. The results suggest that the majority of these countries’ inflation rates can be characterized by mean reversion during the floating exchange rate period. Many of them appear to be nonlinear stationary. This finding is essential in conducting applied economic studies for these countries, when constructing models whose validity relies on whether or not inflation is stationary. The results of this study also imply that shocks to inflation have a transitory effect on inflation in the euro area. Therefore, it would be less costly in exercising the policies of disinflation for the monetary authorities of the euro area than for those of the countries with nonstationary inflation.     

How credible is inflation targeting in Asia? A quantile unit root perspective

This article examines the dynamic behavior of the inflation rate for eight Asian countries using a quantile unit root test. We advocate a three-way definition of inflation targeting based on perfect, imperfect and zero credibility and advance the analysis by incorporating a fully-fledged adoption of inflation targeting. In doing so, we offer new insights by showing that the credibility of inflation targeting and the alternative monetary policy frameworks in Asia are imperfect, except for Malaysia and South Korea under a fully-fledged adoption of inflation targeting. In contrast to past studies that focus on the mean-reversion in inflation rates, we also consider trend-reversion and find that Asian inflation targeting countries have been building up their monetary policy credibility more than the non- inflation targeting countries in terms of a faster rate of decline in inflation rate changes. Our results generally indicate the presence of mean reversion at the lower quantiles only. Where stationarity is present, we find evidence of a varied speed of adjustment process across the quantiles. Finally, we determine the threshold levels whereby inflation becomes stationary and demonstrate that Asian inflation rates generally display stationary behavior during periods of inflation declining or slowing down.     

Is there a unit root in the inflation rate? New evidence from panel data models with multiple structural breaks

In this article, we examine whether or not the inflation rate for 17 OECD countries can be modelled as a stationary process. We find that (1) conventional univariate unit root tests without any structural breaks generally reveal that the inflation rate contains a unit root; (2) the KPSS univariate test with multiple structural breaks reveals that for 10 out of 17 countries inflation is stationary; and (3) the KPSS panel unit root test reveals strong evidence for stationarity of the inflation rate for panels consisting of countries which were declared nonstationary by univariate tests.     

A REVISIT TO THE STATIONARITY OF OECD INFLATION: EVIDENCE FROM PANEL UNIT‐ROOT TESTS AND THE COVARIATE POINT OPTIMAL TEST*

This paper re‐examines the stationarity of inflation rates in 19 Organisation for Economic Cooperation and Development countries with the use of cross‐sectional information. We employ the panel unit‐root tests that allow for cross‐sectional dependency and the covariate point optimal test. These tests have high power in common due to the exploitation of cross‐sectional information, and they can assist mutually to draw a concrete conclusion on inflation dynamics for all series in the panel. Our empirical results show that allowing for cross‐sectional dependency rejects the null hypothesis that all series in the panel have a unit root, implying that there is at least one stationary series in the panel. With the help of the results of the covariate test, we can distinguish the panel into a group of stationary and a group of non‐stationary series. For robustness, the two groups of series are re‐confirmed by the panel tests. Our results reveal evidence of mean reversion in inflation for 15 of 19 countries, which is significantly stronger as compared to that obtained by the state‐of‐the‐art univariate unit‐root tests.     

Asymmetric inflation dynamics: Evidence from quantile regression analysis

This paper applies the regression quantile approach developed by Koenker and Xiao (2004) to investigate the dynamic behavior of inflation in 12 OECD countries. By analyzing the behavior in a wide range of quantiles, this method allows us to quantify the influence of various sizes of shocks that hit the inflation, and is able to capture possible asymmetric adjustment of the inflation towards to its long-run equilibrium. It therefore sheds new lights on the inflation dynamics compared with the conventional unit root methodologies. Our results suggest that generally, the inflation rates are not only mean-reverting but also exhibit asymmetries in their dynamic adjustments, in which large negative shocks tend to induce strong mean reversion, and on the contrary, large positive shocks do not. Policy implications related to the empirical findings are also provided.     

Real interest rate parity with Flexible Fourier stationary test for Central and Eastern European countries

This study applies stationary test with a Fourier function proposed by Enders and Lee (2012) to test the validity of long-run real interest rate parity (RIRP) to assess the non-stationary properties of the real interest rate convergence for twelve Central and Eastern European (CEE) countries. We find that our approximation has higher power to detect U-shaped breaks and smooth breaks than linear method if the true data generating process of interest rate convergence is in fact a stationary non-linear process. We examine the validity of RIRP from the non-linear point of view and provide robust evidence clearly indicating that RIRP holds true for nine CEE countries. Our findings point out that their interest rate adjustment is mean reversion towards RIRP equilibrium values in a non-linear way.     

DO REAL INTEREST RATES REALLY CONTAIN A UNIT ROOT? MORE EVIDENCE FROM A BOOTSTRAP COVARIATE UNIT ROOT TEST

This paper re‐examines the empirical finding that international real interest rates usually have a unit root. This conclusion is put forth in Rapach and Weber (2004 ), using the Ng and Perron (2001 ) tests. We use Rudebusch's (1993 ) approach to construct the small sample distributions of the Ng and Perron tests, and calculate their asymptotic sizes, size‐adjusted powers and rejection rates. These numbers show that the lack of power in the Ng and Perron tests might account for the findings of Rapach and Weber (2004 ): that the unit root null cannot be rejected for most OECD countries. Size distortions are mild in the case of Ng and Perron tests for two series, but are serious for the Phillips and Perron Z‐test on inflation rates. We then apply a powerful covariate augmented Dickey–Fuller unit root test to examine the series for which stationarity cannot be determined with the Ng and Perron tests. The bootstrap technique is also used to control possible size distortions. In contrast to the results of Rapach and Weber (2004 ), the bootstrap covariate augmented Dickey–Fuller test yields striking evidence that real interest rates are stationary for 14 of 16 OECD countries, because nominal interest rates are stationary for the 14 countries, while inflation rates are stationary for all countries.     

Threshold,smooth transition and mean reversion in inflation: New evidence from European countries

Knowing the absence or presence of a unit root in inflation is helpful not only in distinguishing between different economic hypotheses but is also important to monetary authorities in implementing the policies of disinflation. Using data for fourteen European countries, this study investigates the issue of nonstationarity in inflation by considering the possibility of nonlinearity. In particular, we consider the properties of a threshold, smooth transition and structural break in testing for a unit root in the inflation rates. By and large, the results support the view that the inflation rates of the European countries are characterized by a unit root process based on the conventional linear unit root tests. However, the results of the nonlinear unit root tests show that the inflation rates are characterized by nonlinear mean reversion after considering the nonlinear properties of the threshold, smooth transition and structural break. The mean reversion in inflation favors the hypothesis of, for example, the natural rate of inflation and the sticky-price model and implies that shocks only have transitory effects.     

Real interest rates: nonlinearity and structural breaks

Real interest rate is a crucial variable that determines the consumption, investment and saving behavior of individuals and thereby acts as a key policy tool that the central banks use to control the economy. Although many important theoretical models require the real interest rates to be stationary, the empirical evidence accumulated so far has not been able to provide conclusive evidence on the mean reverting dynamics of this variable. To resolve this puzzle we re-investigate the stochastic nature of the real interest rates by developing unit root tests for nonlinear heterogeneous panels where the alternative hypothesis allows for a smooth transition between deterministic linear trends around which stationary asymmetric adjustment may occur. When the newly developed panel unit root tests are applied to the real interest rates of the 17 OECD countries, we were able to uncover overwhelming empirical support in favor of mean reversion in the short-run and long-run real interest rates. Therefore, these results show that the conclusions drawn from a miss-specified test that ignores the presence of either nonlinearity, structural breaks or cross sectional dependence can give quite misleading results about the stochastic behavior of the real interest rates.     

Revisiting Purchasing Power Parity in OECD

This study revisits Purchasing Power Parity theory (PPP) in the 34 OECD countries during January 1994–August 2013. We use a new panel stationary test with both sharp breaks and smooth shifts, a novel approach to panel unit-root testing, proposed by Bahmani–Oskooee et al. (2014). The results indicate that the PPP holds in half of the 34 OECD countries. These results indicate the importance of proper modelling of both sharp breaks and smooth shifts in real effective exchange rate series of OECD countries.     

Assessment of innovation and foreign direct investment: An investigation of OECD countries

Using a panel cointegration method incorporating structural breaks and cross-sectional dependence, this paper explores the long-run equilibrium relationship between innovation and foreign direct investment (FDI) in 30 OECD countries. The results from the panel stationary test show that FDI and innovation variables follow a stationary process with several structural breaks over the period 1999–2018. The results also suggest an equilibrium relationship with structural breaks between FDI and innovation in OECD countries. The panel dynamic OLS model with breaks further reveals that FDI is positively associated with innovation performance and vice versa in OECD countries. Therefore, this paper sheds light on the relationship between FDI and innovation in OECD countries.     

Nominal and real convergence between the CEE countries and the EU: a fractional cointegration analysis

This paper examines the real and nominal convergence between the Central and Eastern European countries and the EU, using fractional cointegration analysis for the period 1980–2003. Fractional cointegration analysis is a flexible methodology, which allows for more subtle forms of mean reversion. The tests performed are those of Geweke and Porter-Hudak. The convergence processes are valid when macroeconomic time series used in the study are fractionally cointegrated. The results indicate that inflation and interest rates series of six sample countries are fractionally cointegrated with those of the EU. Therefore, nominal convergence has been achieved by some of the transition countries, but the equilibrium errors display long memory. Results also indicate that industrial outputs of most countries in the sample are not fractionally cointegrated with that of the EU. The results further indicate that both nominal and real convergence have been achieved only for Hungary.     

Modeling the behaviour of inflation deviations from the target

This study tests for and models non-linearities in inflation deviations from the target in five OECD countries that adopted inflation targeting over the 1990s. Our tests reject the linearity hypothesis and we show that the exponential smooth transition autoregressive (ESTAR) model is capable of capturing the non-linear behavior of inflation misalignments. The extent of inflation deviations from the target varies across the OECD countries, with countries that consistently undershoot the target having a rapid adjustment process, whereas countries that overshoot the target have a slower revision back to equilibrium. Out-of-sample forecasts from the ESTAR model outperform the Markov regime-switching model.     

Do inflation targets anchor inflation expectations?

We suggest a simple test of whether an inflation target anchors private-sector inflation expectations. The test is easy to compute and it is robust to various sources of misspecification. The test may be a useful alternative to dispersion measures commonly studied in research on inflation targeting. Using data for 22 inflation targeting countries, we find for many countries that the forecasters scatter their inflation forecasts away from the inflation target. We account for the endogeneity of inflation targets, we study the variability of our finding across countries and across time, and we study to which extent our results depend on the level and variability of inflation targets.     

Purchasing power parity for fifteen Latin American countries: Stationary test with a Fourier function

This study applies a stationary test with a Fourier function, proposed by Becker et al. (2006), to test the validity of long-run purchasing power parity (PPP) in fifteen Latin American countries over the period of December 1994 to February 2010. The empirical results from the univariate unit root tests indicate that PPP does not hold for these fifteen countries under study. However, a stationary test with a Fourier function indicates that PPP is valid for four of these 15 Latin American countries and they are Brazil, Chile, Ecuador and Uruguay. These results have important policy implications for these fifteen Latin American countries under study.     

Is the consumption-income ratio stationary in African countries? Evidence from new time series tests that allow for structural breaks

This article examines whether the consumption-income ratio is stationary in 50 African countries. We use the residual augmented least squares (RALS-LM) unit root test that allows for structural breaks. The empirical evidence shows that the consumption income ratio is stationary around structural breaks in most (44 out of 50) African countries. This is consistent with the predictions of most economic theories. The general finding of mean reversion implies that (policy) shocks are likely to have only temporary effects on the consumption-income ratio in most African countries .     

Bootstrapping covariate stationarity tests for inflation rates

This paper investigates the stationarity properties of international inflation rates by bootstrapping two stationarity tests with covariates in Jansson (2004). When the asymptotic critical values are used, the two powerful tests are found to reject the null hypothesis less in the presence of a large negative moving-average (MA) error in inflation. To cope with this problem, a parametric bootstrap scheme is developed and then is investigated by a Monte Carlo study. The simulation results demonstrate that the bootstrap tests display a better control over the empirical rejection rates at finite samples. Furthermore, after applying these tests to the inflation in G-10 countries, we find that one of the two tests using bootstrap critical values yields inferences that differ from when using asymptotic ones, and as a whole, the bootstrap tests consistently provide strong evidence in support of mean reversion in inflation in most countries of the G-10.     

Purchasing power parity with flexible Fourier stationary test for Central and Eastern European countries

This study applies stationary test with a Fourier function proposed by Enders and Lee (2004, 2009) to test the validity of long-run Purchasing Power Parity (PPP) to assess the nonstationary properties of the Real Exchange Rate (RER) for seven Central and Eastern European Countries (CEECs). We find that our approximation has higher power to detect U-shaped breaks and smooth breaks than linear method if the true data generating process of exchange rate is in fact a stationary nonlinear process. We examine the validity of PPP from the nonlinear point of view and provide robust evidence clearly indicating that the PPP holds true for all CEECs. Our findings point out their exchange rate adjustment is mean reversion towards PPP equilibrium values in a nonlinear way.