Testing for structural change in the dynamic adjustment model with autoregressive errors

The dynamic CUSUM test for structural change proposed by Kr?mer, Ploberger and Alt (1988) is investigated when the errors are serially correlated in a linear dynamic model. We show that the dynamic CUSUM test can be modified to allow for serial correlation in the disturbance using the same procedure as in Kao and Ross (1995), and that the modified dynamic CUSUM test retains its asymptotic significance levels. Monte Carlo results suggest that the empirical size of the dynamic CUSUM test is highly distorted while the empirical size of the modified dynamic CUSUM test is fairly robust to the change on the degree of autocorrelation. We also find that the power of the modified test essentially depends on the angle between the mean regressors and the structural shift. First version received: April 1997/Final version received: January 1998     

Stability of the money demand function in Asian developing countries

Previous studies that estimated the money demand function in Asian developing countries either employed traditional estimation techniques or recently popularized cointegration technique. While the first group suffers from ‘spurious regression’ problems, the second group interpreted their finding of cointegration as a sign of stability of estimated parameters. This study, after incorporating the CUSUM and CUSUMSQ tests into cointegration analysis, shows that in some Asian countries even though real M1 or M2 monetary aggregates are cointegrated with their determinants, the estimated parameters are unstable.     

A CUSUM test for a long memory heterogeneous autoregressive model

A CUSUM test is proposed for testing structural breaks in a long-memory heterogeneous autoregressive model. The limiting distribution of the CUSUM test is shown to be a simple function of a standard Brownian bridge, contrasting with the nuisance parameter dependent asymptotics of other CUSUM tests based on fractional integration models. A Monte-Carlo experiment investigates finite sample size and power of the test. The proposed test is applied to a set of daily realized volatilities of the log-return of the Korean Won US Dollar exchange rate to reveal some evidence of a break in addition to a long-memory.     

Power monotonicity in detecting volatility levels change

We show that the CUSUM and LM tests for structural change in the volatility process enjoy monotonic power. The framework is general including many recently proposed non-stationary GARCH-type models. The result is in contrast to the well-known issue of non-monotonic power for the CUSUM-based tests for changing mean. Simulations and an empirical example provide further support.     

How stable is the demand for money in Greece?

Abstract

The cointegration technique is now a common method of estimating any money demand function. Numerous studies that applied this technique to estimate the money demand function in Greece, interpreted their finding of cointegration as a sign of stable money demand. In this paper, after incorporating CUSUM and CUSUMSQ tests into cointegration analysis, we show that even though M1 and M2 monetary aggregates are cointegrated with income and interest rate, the M2 money demand function is unstable while M1 is stable.     

Intertemporal sustainability of current account imbalances: New evidence from the OECD countries

This study estimates the intertemporal model for the relationship between exports and imports and examines the sustainability of current account deficits (CADs) and the validity of intertemporal budget constraint for 24 Organisation for Economic Co‐operation and Development countries. The standard ordinary least squares (OLS)‐based two‐step Engle and Granger test, the cointegration regression Durbin–Watson (CRDW) test, and the Stock–Watson test performed on the one‐regime model with time‐invariant parameters and no structural break provide mixed support for the presence of cointegration between exports and imports. The recursive least squares‐based cumulative sum of recursive residuals (CUSUM) and the cumulative sum of squares of recursive residuals (CUSUMSQ) tests and the OLS‐based Andrews‐Quandt (AQ) and Andrews – Ploberger (AP) tests suggest the presence of structural breaks in the long‐run relationship between exports and imports for a number of countries. The end‐of‐sample new cointegration breakdown tests performed on the OLS, fully modified OLS, and full‐information maximum‐likelihood estimates of the model suggest the presence of cointegration between exports and imports for most countries. The dominant support for cointegration between trade flows points toward the sustainability of CADs and the validity of intertemporal budget constraint. The macroeconomic stabilization policies seem to have been effective in correcting the market failures and maintaining the steady‐state equilibrium relationship between trade flows in the sample countries. The findings of this study have important implications for empirical research. The structural breaks in the cointegrating vector could occur even over the short time periods and at any point in time. It is essentially important to assess the sustainability of the external position in the presence of long‐period as well as short‐period breaks in the cointegrating vector.     

Bilateral and regional trade elasticities of the EU

The traditional way of assessing the impact of currency depreciation and income on the trade balance has been to estimate the elasticity of trade volume to relative prices and income. The previous studies examine the problems associated with using aggregate data. The recent studies rely on bilateral data, yet another problem is that data for export and import prices are not available. Thus, this study proposes an alternative way of assessing the impact of currency depreciation by using the real exchange rate and the impact of income on bilateral trade. The models are applied between the EU and its major trading partners. Furthermore, the analysis includes the six major trading regions along side the eight major trading countries for 1980–2007, on the quarterly basis. This article uses the autoregressive distributive lag (ARDL) approach advocated by Pesaran and Pesaran (1997). Our results indicate a higher importance of income compared to the real exchange rate in defined bilateral export and import demand functions. In addition, the applied CUSUM and CUSUMSQ stability tests confirm the stability of estimated coefficients in most cases.     

Mean adjustment and the CUSUM test for structural change

We show that the common practice of mean adjusting the data prior to regression and testing has serious implications for the null distribution of the CUSUM test for structural change.     

Coal consumption: An alternate energy resource to fuel economic growth in Pakistan

This study is an attempt to revisit the causal relationship between coal consumption and economic growth in case of Pakistan. The present study covers the period of 1974–2010. The direction of causality between the variables is investigated by applying the VECM Granger causality approach. Our findings have exposed that there exists bidirectional Granger causality between economic growth and coal consumption. The Cumulative Sum (CUSUM) and Cumulative Sum of Square (CUSUMSQ) diagrams have not found any structural instability over the period of 1974–2010.     

Testing for parameter stability in structural econometric relationships

This letter discusses CUSUM and CUSUM of squares tests for parameter stability in an equation which forms part of a structural simultaneous equations model.     

Remittances and investment nexus in Bangladesh: an ARDL bounds testing approach

Bangladesh is the 8th largest remittance recipient country in the world and one of the heavily dependent (11 % of GDP) countries of remittances. Despite its importance in policy making in developing countries like Bangladesh, there is absence of any study regarding the effect of remittances on the level of investment. In an attempt to fill the gap, we examine the cointegrating property and stability of the relationship among these variables using the ARDL bounds testing approach combined with CUSUM and CUSUMSQ tests. Our findings show that both remittances and trade openness positively and significantly influence the level of investment in Bangladesh, meaning that contrary to most conclusions found in the literature, migrant remittances in developing countries are not entirely spent in basic consumption needs. We also find that foreign aid has very little and insignificant impact on investment. Finally, we find long-run unidirectional causal relationship running from remittances to investment indicating that favorable policies to increase the flow of remittance will promote investment in Bangladesh.     

A new test for structural change

In this paper we are interested in detecting structural change at an unknown point. We argue that the CUSUM test may not ideal for this, and propose an alternative test. Critical values for this test are determined based on the multiple studentt test procedure. A Monte Carlo study suggests that the new test is quite powerful when the structural change occurs in the latter part of the sample. The new test also provides information about the location of structural change.     

A modification of the CUSUM test in the linear regression model with lagged dependent variables

We consider testing for structural change in a dynamic linear regression model, and show that the well known CUSUM test, which has been initially devised only for the standard static model, can easily be modified such as to remain asymptotically valid also in this nonstandard situation.     

CO2 emissions,output, energy consumption,and trade in Tunisia

This article contributes to the literature by investigating the dynamic relationship between carbon dioxide (CO₂) emissions, output (GDP), energy consumption, and trade using the bounds testing approach to cointegration and the ARDL methodology for Tunisia over the period 1971–2008. The empirical results reveal the existence of two causal long-run relationships between the variables. In the short-run, there are three unidirectional Granger causality relationships, which run from GDP, squared GDP and energy consumption to CO₂ emissions. To check the stability in the parameter of the selected model, CUSUM and CUSUMSQ were used. The results also provide important policy implications.     

An Artificial Neural Network Test For Structural Change With Unspecified Parametric Form

Tests for a structural change of unknown timing in parameterized regression functions have been introduced previously under the maintained assumption that the models are correctly specified. However, the existing family of tests are unable to discriminate between structural change and misspecification. This paper introduces test statistics which do not require specification of the parametric form of the underlying data-generating process (DGP). I approximate it by a version of artificial neural networks (ANN). My simulation studies indicate that an ANN approximates the DGP quite well and that the derived tests have good power relative to the power envelope.
JEL Classification Numbers: C12, C14, C45.     

Tests for cointegration with two unknown regime shifts with an application to financial market integration

It is widely agreed in empirical studies that allowing for potential structural change in economic processes is an important issue. In existing literature, tests for cointegration between time series data allow for one regime shift. This paper extends three residual-based test statistics for cointegration to the cases that take into account two possible regime shifts. The timing of each shift is unknown a priori and it is determined endogenously. The distributions of the tests are non-standard. We generate new critical values via simulation methods. The size and power properties of these test statistics are evaluated through Monte Carlo simulations, which show the tests have small size distortions and very good power properties. The test methods introduced in this paper are applied to determine whether the financial markets in the US and the UK are integrated.      

A wavelet-based panel unit-root test in the presence of an unknown structural break and cross-sectional dependency,with an application of purchasing power parity theory in developing countries

This article introduces two different non-parametric wavelet-based panel unit-root tests in the presence of unknown structural breaks and cross-sectional dependencies in the data. These tests are compared with a previously suggested non-parametric wavelet test, the parameteric Im-Pesaran and Shin (IPS) test and a Wald type of test. The results from the Monte Carlo simulations clearly show that the new wavelet-ratio tests are superior to the traditional tests both in terms of size and power in panel unit-root tests because of its robustness to cross-section dependency and structural breaks. Based on an empirical Central American panel application, we can, in contrast to previous research (where bias due to structural breaks is simply disregarded), find strong, clear-cut support for purchasing power parity (PPP) in this developing region.     

Fourier ADL cointegration test to approximate smooth breaks with new evidence from Crude Oil Market

Economic data is typically subject to a number of different forms of structural breaks. Ignoring structural breaks in a model can lead to misspecification issues and false conclusions. This paper proposes a new Autoregressive Distributive Lag (ADL) cointegration test in the presence of nonlinear breaks approximated by a Fourier function. The test offers a simple way to capture smooth structural change in time series data. Exact break dates are not required, and the suggested methodology can accommodate unknown number and form of gradual structural change. The testing procedure circumvents the potential power loss which can result from adding more dummy variables in the testing equation. Simulation results show that our procedure has good size and power properties. We demonstrate our test on the empirical example of real oil prices, oil production, and real economic activity, which are subject to structural breaks. The new test suggests that variables are cointegrated, while a conventional ADL test ignores structural breaks and concludes the opposite. This result casts some doubt on conventional oil price models.     

Detecting cointegration relationships under nonlinear models: Monte Carlo analysis and some applications

Testing for cointegration in the presence of nonlinear adjustments or structural breaks is important for examining the equilibrium relationship among economic variables. It is known that standard cointegration tests perform poorly when a cointegration relationship has nonlinear adjustments or structural breaks. However, it is not clear how some cointegration tests allowing for nonlinearity perform under other classes of nonlinear cointegration models. This paper investigates which cointegration tests help detect a cointegration relationship with nonlinear adjustments or structural breaks. Our Monte Carlo simulation results demonstrate that the cointegration test with threshold adjustment generally has better power performance under most cointegration relationships with nonlinearity. We also provide empirical applications to the money demand and term structure of the U.S. interest rates. The empirical results show that the test allowing for threshold adjustment provides strong evidence of the cointegration relationships of money demand and the term structure of interest rates.     

Testing for weak-form efficiency of crude palm oil spot and future markets: new evidence from a GARCH unit root test with multiple structural breaks

There is a sizeable literature that tests for weak-form efficiency in commodity and energy spot and future prices. While many studies now allow for multiple structural breaks to address the criticism that conventional unit root tests have low power to reject the unit root null in the presence of structural change, the extant literature overlooks the fact that conventional unit root tests are biased in the presence of conditional heteroscedasticity. We apply a recently developed generalized autoregressive conditional heteroscedasticity (GARCH) unit root test with multiple structural breaks to crude palm oil spot and future prices and find much more evidence against weak-form efficiency than that found using tests that fail to allow for conditional heteroscedasticity. Our results point to the importance of allowing for heteroscedasticity when testing for efficiency in commodity and energy spot and future prices.