Does GNP have a unit root?: A re-evaluation

Stock and Watson (1986) test the hypothesis that real per capita GNP has a unit root by using a test statistic due to Phillips (1985) which incorporates a non-parametric correction for the serial correlation induced by system and error dynamics. The version of this test that is used by Stock and Watson does not accomodate the presence of a drift, and to compensate, they detrend the series by extracting a 1.5% annual trend growth. We use a version of this class of non-parametric tests, developed by Phillips and Perron (1986), which allows for an estimated drift, and reassess the Stock and Watson findings.     

Does real U.K. GDP have a unit root? Evidence from a multi-century perspective

ABSTRACT

We employ linear and nonlinear unit-root tests to examine the stationarity of five multi-century historical U.K. series of real output compiled by the Bank of England. Three series span 1270 to 2016 and two series span 1700 to 2016. These datasets represent the longest span of historical real output data available and, thus, provide the environment for which unit-root tests are most powerful. A key feature of our test is its simultaneous allowance for two types of nonlinearity: time-dependent (structural breaks) nonlinearity and state-dependent (asymmetric adjustment) nonlinearity. The key finding of the test, contrary to what other more popular nonlinear unit-root tests suggest, provides strong evidence that the main structure of the five series is a stationary process characterized by an asymmetric nonlinear adjustment and a permanent break affecting both the intercept and the trend. A major policy implication of this finding is fiscal and/or monetary stabilization policies have only temporary effects on the output levels of the United Kingdom.     

Does Purchasing Power Parity hold? New evidence from wild-bootstrapped nonlinear unit root tests in the presence of heteroskedasticity

In spite of the extensive research which has already been undertaken, the issue as to whether Purchasing Power Parity (PPP) empirically holds, continues to be strongly debated. Existing studies have been criticized for their reliance on unit root tests which are deemed to suffer from certain weaknesses such as the size distortion bias arising from heteroskedasticity. In this paper, we provide new evidence on PPP based on a new methodology that overcomes this problem. We use the widely accepted KSS (Kapetanios et al., 2003) non-linear unit root tests which we, however, wild bootstrapped. Through Monte Carlo simulation, we demonstrate that the wild-bootstrapped KSS is robust to heteroskedasticity-induced size distortion problem. We apply this method to test PPP across 61 countries over the period 1994 to 2012 — a period characterized by a number of crises such as the Asian Financial Crisis, Russian Crisis, dotcom crisis, Global Financial Crises, among others, and therefore, intense heteroskedasticity. Our results provide strong evidence against PPP. This paper contributes to both the international financial economics and econometrics literatures.     

Do Balkan economies catch up with EU? New evidence from panel unit root analysis

This paper explores empirically the issue of income convergence for the Balkans over the period 1994–2011 and the investigation relies on income differentials from both the averages of the European Union’s-15 (EU-15) and the European Union’s-24 (EU-24) as well as within the Balkan group. The adopted methodology deploys the non stationary panel unit root framework to cope with the problem of limited sample providing more reliable insight and, in particular, the analysis uses the univariate and panel minimum Lagrange Multiplier (LM) unit root tests, suggested by Lee and Strazicich (2003, 2004) and Im et al. (2005), that accounts for one and two endogenously determined structural breaks. The overall evidence is in favor of catching up with the EU benchmark cases as well as in favor of convergence within the Balkan area. However, disparities for some countries are confirmed.     

Is there really hysteresis in the OECD unemployment rates? New evidence using a Fourier panel unit root test

Empirica - We investigate the hysteresis hypothesis by proposing a heterogeneous panel unit root test that allows for gradually changing trends and cross-sectional dependence (CSD) among panel...     

Does the digital divide across countries lead to convergence? New international evidence

We examine the convergence of information and communication technologies (ICT) among 47 developed and emerging countries using annual data from 2000 to 2012. We construct an ICT development index using a principal component analysis. The results, based on a dynamic panel data model, reveal a divergence in ICT development. This study identifies two factors that drive a country's digitalization divergence level: the growth of per capita income and the ratio of urban to rural population. In addition, ICT divergence is higher in emerging countries than in developed countries.     

Are state–local government expenditures converging? New evidence based on sequential unit root tests

Large and persistent gaps in subnational public expenditure have important implications regarding growth, equity, and migration. In this context, we revisit the question of expenditure convergence across the American states to provide more nuanced evidence than found by a small number of previous studies. We employ a methodology due to Smeekes (Bootstrap sequential tests to determine the stationary units in a panel, 2011) that sequentially tests for unit roots in pairwise (real per capita) expenditure gaps based on user specified fractions. In a panel of 48 combined state–local government units (1957–2008), we found that expenditures on highways, sanitation, utility, and education were far more convergent than expenditures on health and hospitals, police and fire protection, and public welfare. There was little evidence of “club convergence” based on the proportion of intraregional convergent pairs. Several historically high-grant receiving states showed relatively strong evidence of convergence. Our results bode well for future output convergence and opportunities for Tiebout-type migration across jurisdictions. They also imply a diminished role for public infrastructure and education spending in business location choices over time and a mixed role for federal grants in inducing convergence.     

Does taxation have real effects on agricultural output? Theory and empirical evidence from China

China has a long history of taxing agriculture, with special levies on output. Whether farm households are taxed on a lump-sum basis or as a proportion of output is an important issue. This paper develops a theoretical model to understand better the effects of the lump-sum and proportional taxation on agricultural output. It then empirically investigates the predictions using tax and output data on Chinese agriculture. The theoretical model predicts that lump-sum taxation affects only consumption, while proportional taxation simultaneously affects consumption, capital inputs and final output. Although the main tax policy targeted output, our results suggest that taxation had only a modest impact on output since it was effectively applied as lump sum taxation brought about by localized levies and taxes.     

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.     

Are the Australian and New Zealand stock prices nonlinear with a unit root?

Whether or not stock prices are characterized by a unit root has important implications for policy. For instance, by applying unit root tests one can deduce whether stock returns can be predicted from previous changes in prices. A finding of a unit root implies that stock returns cannot be predicted. This paper investigates whether or not stock prices for Australia and New Zealand can be characterized by a unit root process. An unrestricted two-regime threshold autoregressive model is used with an autoregressive unit root. Among the main results, it is found that the stock prices of both countries are nonlinear processes that are characterized by a unit root process, consistent with the efficient market hypothesis.     

Does PPP hold in African countries? Further evidence based on a highly dynamic non-linear (logistic) unit root test

With a view to investigating whether the purchasing power parity (PPP) theory holds true for selected African countries during the January 1980–December 2003 period, we employ a rigorous, highly dynamic non-linear (logistic) unit root test, as first advanced by Leybourne et al. (1998 Leybourne, S, Newbold, P and Vougas, D. 1998. Unit roots and smooth transitions. Journal of Time Series Analysis, 19: 83–97. [Crossref] , [Google Scholar]), which is considerably more powerful than those tests traditionally used. Compared with the rejection of the null of the unit root process for only one of the 22 countries under study when we use the traditional ADF, PP, KPSS, NP and the DF-GLS unit root tests, with the Leybourne et al. (1998 Leybourne, S, Newbold, P and Vougas, D. 1998. Unit roots and smooth transitions. Journal of Time Series Analysis, 19: 83–97. [Crossref] , [Google Scholar]) test, we strongly reject the null of the unit root process for a surprising six of the 22 countries. These empirical results clearly indicate that PPP holds true for these six countries, namely the Central African Republic, the Côte d’Ivoire, Kenya, Madagascar, Uganda and Lesotho.     

Does the educational management model matter? New evidence from a quasiexperimental approach

A growing literature has appeared in the last 2 decades with the aim to explore if the way in which publicly funded private schools are managed (a ver     

Convergence in income inequality? evidence from panel unit root tests with structural breaks

This paper empirically tests whether there is evidence of convergence in income inequality, as predicted by several versions of the neoclassical growth model, using a large panel of annual data for the 48 contiguous states in the US over the 1916?C2005 period. By implementing the panel LM unit root test developed by Im et?al. (Oxford Bull Econ Stat 67:393?C419, 2005, Panel LM unit-root tests with trend shifts, Mimeo, 2010) that allows for the presence of structural breaks and heterogeneity in the panel, we find overwhelming evidence in support of convergence in income inequality. In addition, the results are robust to alternative inequality indicators used, different notions of stochastic convergence defined, and additional cross-sectional correlation considered.     

Do hours worked contain a unit root? Evidence from panel data

The aim of the present paper is to provide cross country evidence of the non-stationarity of hours worked for OECD countries. For this purpose, panel unit root tests are employed to improve power against univariate counterparts. Since cross section correlation is a distinct feature of the underlying panel data, results are based on various second generation panel unit root tests, which account for cross section dependence among units. If an unobserved common factor model is assumed for generating the observations, there is indication for both a common factor and idiosyncratic components driving the non-stationarity of hours worked. In addition, taking these results together, there is no indication of cointegration among the individual time series of hours worked.     

Does foreign direct investment transfer technology across borders? New evidence

Based on industry-level data of seventeen OECD countries we examine FDI as a potential channel for knowledge diffusion. We find that FDI-receiving countries benefit strongly from FDI-related knowledge spillovers. We do not find evidence for positive outward-FDI-related technology sourcing effects.     

Rationality of inflation–output forecasts of MMS survey: international evidence

We analyse the individual rationality of inflation and output forecasts from Money Market Survey (MMS) for a group of G7 countries and EU under asymmetric univariate Linlin and Linex loss functions. We also test for joint rationality of inflation–output forecasts using the forecast rationality test under multivariate asymmetric loss functions proposed by Ulu (2013). Our results indicate that rationality is often rejected under symmetric loss, and results improve towards rationality when asymmetric loss functions are assumed. The assumption of multivariate asymmetric loss compared to univariate asymmetric loss provides further evidence towards rationality. We also analyse directional forecast accuracy of the inflation and output forecasts and find that the inflation–output forecasts of MMS are valuable when considered both jointly and separately.     

Does prenatal WIC participation improve birth outcomes? New evidence from Florida

We study the effects of prenatal receipt of nutritional and educational services provided by the Supplemental Nutrition Program for Women, Infants, and Children (WIC) on birth outcomes. Our identification strategy consists of two elements: (1) identifying families in a very tight income range surrounding the WIC eligibility threshold; and (2) exploiting a policy change that differentially influenced the WIC takeup rates of the families on each side of the eligibility threshold. We conduct this analysis by merging three large statewide administrative datasets from Florida concerning all births during the period 1997–2001. We match the birth records of infants and the school records of their older siblings in order to relatively precisely identify “marginally eligible” and “marginally ineligible” families that are very similar in their observable characteristics. We find that WIC participation has no effect on mean birth weight and gestational age, but substantially reduces the likelihood of adverse birth outcomes, e.g. birth weights below 2500 g.