An empirical note about additive outliers and nonstationarity in Latin-American inflation series

This note shows the empirical dangers of the presence of large additive outliers when testing for unit roots using standard unit root statistics. Using recent proposed procedures applied to four Latin-American inflation series, I show that the unit root hypothesis cannot be rejected.Jel classification: C2, C3, C5I want to thank Pierre Perron for useful comments on a preliminary version of this paper. Helpful comments from an anonymous referee, and Yiagadeesen Samy are appreciated. I thank the Editor Baldev Raj for useful comments about the final structure of this paper. Finally, I also thank André Lucas for helpful suggestions concerning the use of his nice computer program Robust Inference Plus Estimation (RIPE).First revision received: August 2001/Final revision received: December 2002     

Unit Root Tests for Dependent Micropanels

This paper proposes a new test for the null hypothesis of panel unit roots for micropanels with short time dimensions (T) and large cross‐sections (N). There are several distinctive features of this test. First, the test is based on a panel AR(1) model allowing for cross‐sectional dependency, which is introduced by a factor structure of the initial condition. Second, the test employs the panel AR(1) model with AR(1) coefficients that are heterogeneous for finite N. Third, the test can be used both for the alternative hypothesis of stationarity and for that of explosive roots. Fourth, the test does not use the AR(1) coefficient estimator. The effectiveness of the test rests on the fact that the initial condition has permanent effects on the trajectory of a time series in the presence of a unit root. To measure the effects of the initial condition, the present paper employs cross‐sectional regressions using the first time‐series observations as a regressor and the last as a dependent variable. If there is a unit root in every individual time series, the coefficient of the regressor is equal to one. The t‐ratios for the coefficient are this paper's test statistics and have a standard normal distribution in the limit. The t‐ratios are based on the OLS estimator and the instrumental variables estimator that uses reshuffled regressors as instruments. The test proposed in this paper makes it possible to test for a unit root even at T = 2 as long as N is large. Simulation results show that test statistics have reasonable empirical size and power. The test is applied to college graduates' monthly real wage in South Korea. The number of time‐series observations for this data is only two. The null hypothesis of a unit root is rejected against the alternative of stationarity.     

City CPI Convergence in Mexico

This paper tests the purchasing power parity hypothesis within a single developing country currency area: Mexico. This work stems from research in comparing price movements across countries and a growing literature on price dynamics within a single currency area. The author uses city Consumer Price Index data for 34 cities in Mexico over the period 1982–2000. He followed the standard procedure of testing for I(1) processes in relative city prices, or city real exchange rates, using univariate and panel unit root tests. The main results of the paper are: First, Mexican city relative prices are stationary—the data rejects the hypothesis that city real exchange rates contain a random walk, but only using panel unit root techniques. Finally, regional demand and supply homogeneity implies stronger evidence for price parity within regions, while there is considerable evidence of regional price convergence, regional homogeneity does not guarantee faster convergence.     

BOOTSTRAPPING COVARIATE UNIT ROOT TESTS: AN APPLICATION TO INFLATION RATES

This paper proposes a bootstrap procedure for the covariate point optimal tests (CP_T) of Elliott and Jansson. Although the covariate tests enjoy large power gains over the traditional univariate unit root tests, our simulations show that they still suffer from severe size distortions at finite samples. Through simulations, we demonstrate the superiority of the bootstrap procedure in the sense that it can yield desirable size and power properties for the CP_T tests when the Akaike's information criterion is used. Moreover, we show the empirical relevance of the bootstrap tests by applying them to inflation in the G‐10 countries, and then obtain strong evidence against the unit root hypothesis for most countries at the 5% significance level.     

Alternative lag length selection criteria and the split-trend stationarity hypothesis

This study asks whether evidence that key macroeconomic time series are stationary around broken trends is robust to using different criteria to determine the lag length in the ADF regressions. When lag lengths are determined using the Schwarz criterion or two different specific-to-general methods, tests for unit roots in several series in the Nelson-Plosser (1982) data and in US postwar real GNP find weaker evidence against the unit root hypothesis than either Perron (1989), who set the date for the break in the trend a priori or Zivot and Andrews (1992), who determined the break date endogenously.     

On the joint Fourier–ESTAR testing of PPP

The purchasing power parity (PPP) is the hypothesis that the real exchange rate series are stationary. This study briefly reviews and applies six competing unit root test procedures to test PPP. Reflecting the existing literature, the results are mixed. The Kiliç test is the most favourable while the Kapetanios, Shin, and Snell (KSS) test is the least favourable to PPP and the standard ADF test lies in between. The same conclusion applies to the Fourier extensions of those three tests. The results support a recently suggested F-test for the significance of Fourier terms in unit root test equations.     

The burden of blood transfusion: a utilization and economic analysis – a pilot study in patients with chemotherapy-induced anemia (CIA)

Abstract

Objective:

The objective is to measure the burden of blood transfusion of Packed Red Blood Cells (PRBCs) in patients with chemotherapy-induced anemia (CIA) on the institutional outpatient transfusion center.

Methods:

This is a retrospective chart review (starting July 1, 2010, working backwards until 120 evaluable patients are accrued) at a single institutional transfusion center in the US. The mean and standard deviation (SD) were calculated for patient’s age, pre-transfusion Hgb level, and other transfusion-related activities.

Results:

One hundred and twenty records were reviewed. The majority included patients who were female (71%), African American (61%), and had either Medicare (48%) or private insurance (39%). The mean patient age was 59 years and the average pre-transfusion Hgb was 7.9?g/dL. The average patient visit to facility ranged from 213?min for one PRBC unit to 411 minutes for three PRBC units. The mean staff time for patient evaluation was 66 minutes. Actual time for transfusion was ～100?min for each PRBC unit; 90% of patients received two PRBC units. Staff was engaged in direct patient care for an average of 322?min for two PRBC units. The labor cost of transfusion (in 2011 $US) ranged from $46.13–$49.33 per PRBC unit. The estimated fully loaded bundled cost was $596.49 for transfusion of one unit of PRBC. Limitations of the study include: the site included in this study may not be applicable to all sites in practice and the evaluated patient population was varied, with the exception that all patients were treated for some type of malignancy; and the review of blood bank records for 120 patients was not 120 independent events and, as such, may not have adequately captured actual variability.

Conclusions:

This analysis quantifies expense in terms of time for administration of the transfusion, as well as costs associated with outpatient blood transfusions.     

Less frequent dosing of erythropoiesis stimulating agents in patients undergoing dialysis: a European multicentre cost study

Abstract

Objective: To calculate the variable costs involved with the process of delivering erythropoiesis stimulating agents (ESA) in European dialysis practices.

Methods: A conceptual model was developed to classify the processes and sub-processes followed in the pharmacy (ordering from supplier, receiving/storing/delivering ESA to the dialysis unit), dialysis unit (dose determination, ordering, receipt, registration, storage, administration, registration) and waste disposal unit. Time and material costs were recorded. Labour costs were derived from actual local wages while material costs came from the facilities’ accounting records. Activities associated with ESA administration were listed and each activity evaluated to determine if dosing frequency affected the amount of resources required.

Results: A total of 21 centres in 8 European countries supplied data for 142 patients (mean) per hospital (range 42–648). Patients received various ESA regimens (thrice-weekly, twice-weekly, once-weekly, once every 2 weeks and once-monthly). Administering ESA every 2 weeks, the mean costs per patient per year for each process and the estimates of the percentage reduction in costs obtainable, respectively, were: pharmacy labour (€10.1, 39%); dialysis unit labour (€66.0, 65%); dialysis unit materials (€4.11, 61%) and waste unit materials (€0.43, 49%).

Limitation: Impact on financial costs was not measured.

Conclusion: ESA administration has quantifiable labour and material costs which are affected by dosing frequency.     

Market share instability in Brazilian industry: a dynamic panel data analysis

The paper investigates market share instability in the context of Brazilian industry for the 1986–1998 period. The paper proposes the use of panel data unit root tests to access market share instability for a sample of industrial firms from different sectors and therefore generalizes related time series unit root tests proposed by Gallet and List (2001 Gallet, CA and List, JA. 2001. Market share instability: an application of unit root tests for the cigarette industry. Journal of Economics and Business, 53: 473–80.  ). The results mostly indicate that one cannot reject the hypothesis of market share instability and therefore there exist some degree of market rivalry in the Brazilian case.     

Testing for a unit root under the alternative hypothesis of ARIMA (0, 2, 1)

Showing a dual relationship between ARIMA (0,?2,?1) with parameter θ?=??1 and the random walk, a new alternative hypothesis in the form of ARIMA (0,?2,?1) is established in this article for evaluating unit root tests. The power of four methods of testing for a unit root is investigated under the new alternative, using Monte Carlo simulations. The first method testing θ?=??1 in second differences and using a new set of critical values suggested by the two authors in finite samples, is the most appropriate from the integration order point of view. The other three methods refer to tests based on t and?φ?statistics introduced by Dickey and Fuller, as well as, the nonparametric Phillips–Perron test. Additionally, for cases where for the first method a low power is met, we studied the validity of prediction interval for a future value of ARIMA (0,?2,?1) with θ close but greater of ?1, using the prediction equation and the error variance of the random walk. Keeping the forecasting horizon short, the coverage of the interval ranged at expected levels, but its average half-length ranged up to four times more than its true value.     

The P* model and Austrian prices

In theP ^* model the price level is determined by the money stock per unit of potential out-put and the long-run equilibrium level of the velocity of money. This article applies this model to Austria. Problems in identifying permanent shocks to potential output and/or velocity lead to the rejection of such models of the price level, but their first-difference version is not so suspect. While evidence is found of a long-run relationship between Austria inflation and money growth, even the first-difference version of theP ^* model is rejected for Austria. Since Austria is a small economy, closely tied to Germany, the article also investigates whether Austrian prices are tied to a GermanP ^* measure. This hypothesis is also rejected, but there is a statistically-significant long-run relationship between Austrian and German inflation. Moreover, Austrian money growth remains significant even in this relationship.This article was written while the author was a Visiting Scholar at the Austrian National Bank. The author is indebted to Fritz Breuss, W. Jahnke, and Dieter Proske for help in obtaining the data used here, and for useful discussions about the data, relevant theoretical issues and results. The comments of the referees on an earlier version are also gratefully acknowledged. The views expressed here are those of the author and are not necessarily those of the Austrian National Bank, the Federal Reserve Bank of St. Louis, or the Board of Governors of the Federal Reserve System.     

Panel unit root tests under cross section dependence with recursive mean adjustment

Utilizing recursive mean adjustment (RMA) we provide two unit root tests: the covariate RMA unit root test and the panel feasible generalized RMA unit root test. The proposed panel unit root tests are precise and powerful, especially when T > N.     

A confirmatory analysis of the unit root hypothesis for OECD consumption-income ratios

This article investigates the existence of a unit root in the consumption-income ratio for a sample of 23 OECD countries over the period 1960 to 2005. For that purpose, we first use recently developed unit root tests with good size and power. Second, we employ the more powerful panel unit root tests of Pesaran (2003 Pesaran, MH. 2003. A Simple Panel Unit Root Test in the Presence of Cross-Section Dependence mimeo, Cambridge University [Google Scholar]) and Smith et al . (2004) that take the null of nonstationarity and a bootstrap version of the test of Hadri (2000 Hadri, K. 2000. Testing for stationarity in heterogeneous panel data. The Econometrics Journal, 3: 148–61. [Crossref] , [Google Scholar]) that takes stationarity as the null hypothesis. Overall, our confirmatory analysis renders clear-cut evidence that OECD consumption-income ratios contain a unit root.     

HYSTERESIS HYPOTHESIS IN UNEMPLOYMENT AND LABOUR FORCE PARTICIPATION RATES: EVIDENCE FROM AUSTRALIAN STATES AND TERRITORIES *

This article simultaneously investigates the hysteresis hypothesis of unemployment and labour force participation using regional level data in Australia. The conventional univariate and panel unit root tests indicate that the hysteresis hypothesis cannot be rejected for most of the regions in Australia. To further confirm if the hysteresis finding in unemployment and labour force participation results from not considering structural breaks. We employ a panel stationarity test recently developed by Carrion‐i‐Silvestre et al. (2005 ), which considers multiple structural breaks and cross‐sectional dependence. The test results lend support for unemployment hysteresis and participation regime‐wise stationarity. Accordingly, the findings imply that a temporary shock may have permanent effects on the unemployment rate but not on labour force participation in Australia and thus call for policies aimed at improving the adjustment mechanism in unemployment.     

VENTURE CAPITAL AND INNOVATION: WHICH IS FIRST?

Policy‐makers typically interpret positive relations between venture capital (VC) investments and innovations as evidence that VC investments stimulate innovation (VC‐first hypothesis). This interpretation is, however, one‐sided because there may be a reverse causality that innovations induce VC investments (innovation‐first hypothesis): an arrival of new technology increases demand for VC. We analyze this causality issue of VC and innovation in the US manufacturing industry using both total factor productivity growth and patent counts as measures of innovation. We find that, consistent with the innovation‐first hypothesis, total factor productivity growth is often positively and significantly related with future VC investment. We find little evidence that supports the VC‐first hypothesis.     

A simple unit root test against asymmetric STAR nonlinearity with an application to real exchange rates in Nordic countries

Existing tests of the unit root hypothesis against the alternative hypothesis of exponential smooth transition autoregressive (ESTAR) nonlinearity implicitly assume symmetry under the alternative. This paper proposes a simple unit root test against the alternative of symmetric or asymmetric ESTAR nonlinearity. In the event that the unit root hypothesis is rejected, a simple test of symmetric versus asymmetric ESTAR nonlinearity is also proposed. The asymptotic distributions of the test statistics are straightforward to establish and finite-sample performance is studied with Monte Carlo simulations. An empirical application involving the real exchange rates of four Nordic countries against the U.S. dollar illustrates the usefulness of the new tests.     

Testing the permanent-income hypothesis: new evidence from West-German states (Länder)

This paper investigates whether time-series data from 11 West-German states (L?nder) provide evidence in accord with the implication of the permanent-income hypothesis (PIH) for the stochastic relationship between consumption and income innovations. The empirical results do not support this hypothesis, in the sense that the response of consumption to income innovations is found to be much weaker than is predicted by the PIH. Moreover, for each individual state as well as for Germany as a whole, the response was found to be asymmetric, being stronger for negative than positive income innovations. This evidence of asymmetry is consistent with a model in which consumers are liquidity constrained.

Correct cointegration tests of the long-run relationship between nominal interest and inflation

The Fisher (1930) hypothesis suggests that a long-run equilibrium relationship exists between the non-stationary series: nominal interest and expected inflation. Testing such a cointegrating relationship is complicated by the presence of the unobserved ex antereal rate of interest in residuals from the cointegrating regression. Assumptions concerning the stochastic properties of the expected real rate of interest are examined, and two proxies for the ex antereal rate are employed in multivariate cointegration tests of the Fisher hypothesis.     

Convergence to Purchasing Power Parity at the Commencement of the Euro*

We investigate convergence towards purchasing power parity (PPP) within the eurozone and between the eurozone and its main partners using panel data methods. We find strong rejections of the unit‐root hypothesis, and therefore evidence of PPP, in the eurozone for different numéraire currencies, as well as in the eurozone plus the United States with the dollar as the numéraire currency, starting between 1996 and 1999. The process of convergence towards PPP, however, begins earlier, following the currency crises of 1992 and 1993, adoption of the Maastricht Treaty, and official completion of the Single Market.     

Exchange rate pass-through in a small open economy: the Anglo-Irish case

Bilateral import unit values are constructed to investigate the extent and speed of exchange rate and production cost pass-through into the unit values of Irish imports (total and sectoral) from the UK using Menon's (1996 Menon, J. 1996. The degree and determinants of exchange rate pass-through: market structure, non-tariff barriers and multinational corporations. Economic Journal, 106(435): 434–44.  ) mark-up model. The approach used to measure exchange rate pass-through is based on cointegration and error-correction modelling and the period of analysis is from 1979 to 1995. Full pass-through from the bilateral Irish pound–Sterling exchange rate and from UK producer costs could not be rejected for total and sectoral import unit values for the sample period 1979q1–1995q4. This implies no role for domestic competing prices in explaining the long-run relationship determining unit values of Irish imports from the UK. The results indicate that for aggregate and sectoral unit values of Irish imports from the UK pass-through is incomplete in the short-run.